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What are the upper and lower case letters


Upper-case letters Definition & Meaning

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Capital letters. (Compare lower-case letters.)

QUIZ

WILL YOU SAIL OR STUMBLE ON THESE GRAMMAR QUESTIONS?

Smoothly step over to these common grammar mistakes that trip many people up. Good luck!

Question 1 of 7

Fill in the blank: I can’t figure out _____ gave me this gift.

Words nearby upper-case letters

upper bound, Upper Canada, Upper Canadian, Upper Carboniferous, uppercase, upper-case letters, upper chamber, Upper Chinook, upper class, upperclassman, upper crust

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

MORE ABOUT UPPER CASE LETTERS

What are 

uppercase letters?

Uppercase letters are capital letters—the bigger, taller versions of letters (like W), as opposed to the smaller versions, which are called lowercase letters (like w).

Uppercase means the same thing as capital. Uppercase letters can also be called capitals.

Some uppercase letters are just larger, taller versions of their lowercase counterparts (like uppercase W and lowercase w or uppercase C and lowercase c), but in many cases the two versions of the letter take different forms altogether, such as uppercase A and lowercase a or uppercase B and lowercase b.

To capitalize a word is to make its first letter an uppercase letter. For example, to capitalize the word polish (which is here spelled with a lowercase p), you would write it with an uppercase P, as Polish.

The state of being capitalized or uppercase (or the process of making a letter an uppercase letter) is called capitalization, as in Please check your paper for proper punctuation and capitalization.

In English, uppercase letters are used at the beginning of words for a few different reasons. It is considered a standard rule of English to use an uppercase letter to start proper nouns (which are nouns that refer to specific people, places, or things—meaning one’s that have specific names), such as Jess, Mexico, and Nintendo. Using an uppercase letter at the start of a word can change the way the reader interprets its meaning, as in the case of polish (a verb meaning to make something shinier) and Polish (an adjective describing someone from Poland) or apple (the fruit) and Apple (the company).

We also use an uppercase letter for the first letter of the first word in a sentence. Sometimes, we use an uppercase letter for the first letter of each word in a title, as in To All The Boys I’ve Loved Before. This is sometimes called title case.

Some acronyms and abbreviations are written using all uppercase letters, such as NASA and U.S. A word written entirely in uppercase letters (like WHAT) is said to be written in caps or all caps.

Example: A lot of people don’t bother using uppercase letters in text messages unless they want to emphasize something.

Where does 

uppercase letter come from?

The term uppercase letter has been used since at least the 1730s. The words uppercase and lowercase come from printing. The process of physically printing things with printing presses involved trays, called cases, that were divided into compartments for holding different kinds of type (blocks with letters on them). The upper case held capital letters and the lower case held what came to be known as lowercase letters.

It can be confusing to know whether or not to use an uppercase letter in certain situations, but a capitalization guide can help.

Did you know ... ?

What are some other forms related to uppercase letter?

  • upper-case letter (alternate hyphenated spelling)
  • upper case letter (alternate two-word spelling)

What are some synonyms for uppercase letter?

  • capital letter
  • capital
  • uppercase (when uppercase is used as a noun)

What are some words that share a root or word element with uppercase letter?

  • uppercase
  • lowercase
  • lowercase letter
  • letter

What are some words that often get used in discussing uppercase letter?

  • capitalize
  • capitalization
  • spelling
  • first
  • word
  • sentence
  • title

How are 

uppercase letters used in real life?

Uppercase letters are used in the beginning of names and other proper nouns, at the beginning of sentences, at the beginning of words in titles, and in some abbreviations. In casual use, a word might be written in uppercase letters for emphasis.

She’s back with the classics and the riddles and the puzzles. The uppercase letters say APRIL NINTH. 👏🏻 @taylorswift13 You deserve this, so much. 💛 https://t.co/x7KsswdBPj

— anne⁰⁰ ఌ😺 (@ANNEtisocial) February 11, 2021

Identifying and matching uppercase and lowercase letters using these colorful underwater themed cards. Games make learning fun! 🐟 🐠 #IslipENL #LearningIsFun @WingElemIslip pic.twitter.com/QjUSLvuZ57

— Jaclyn Brady (@JaclynBrady17) February 5, 2021

i wonder if i’ll ever use uppercase letters for anything besides emphasis again

— h☼ (@hl_cutie) July 8, 2019

Try using 

uppercase letters!

Which of the following kinds of words is often spelled with an uppercase letter at the beginning?

A. proper nouns
B. the first word in a sentence
C. the first word in a title
D. all of the above

How to use upper-case letters in a sentence

  • Certain features of its history suggest why this may be the case.

    Anti-Fluoriders Are The OG Anti-Vaxxers|Michael Schulson|July 27, 2016|DAILY BEAST

  • And, in the case of fluoride, at least, that doubt might actually be justified.

    Anti-Fluoriders Are The OG Anti-Vaxxers|Michael Schulson|July 27, 2016|DAILY BEAST

  • Her latest book, Heretic: The Case for a Muslim Reformation, will be published in April by HarperCollins.

    Ayaan Hirsi Ali: Our Duty Is to Keep Charlie Hebdo Alive|Ayaan Hirsi Ali|January 8, 2015|DAILY BEAST

  • Their friendship began when Krauss, who was chairman of the physics department at Case Western in Cleveland, sought out Epstein.

    Sleazy Billionaire’s Double Life Featured Beach Parties With Stephen Hawking|M.L. Nestel|January 8, 2015|DAILY BEAST

  • A grand juror in the Ferguson case is suing to be able to explain exactly what went down in the courtroom.

    Politicians Only Love Journalists When They're Dead|Luke O’Neil|January 8, 2015|DAILY BEAST

  • “Perhaps you do not speak my language,” she said in Urdu, the tongue most frequently heard in Upper India.

    The Red Year|Louis Tracy

  • The case was an assault and battery that came off between two men named Brown and Henderson.

    The Book of Anecdotes and Budget of Fun;|Various

  • In this case, I suspect, there was co-operant a strongly marked childish characteristic, the love of producing an effect.

    Children's Ways|James Sully

  • On the upper part of the stem the whorls are very close together, but they are more widely separated at the lower portion.

    How to Know the Ferns|S. Leonard Bastin

  • Sometimes in the case of large plants, cones have been known to occur on the tips of the branches of the Marsh Horsetail.

    How to Know the Ferns|S. Leonard Bastin

What Are Lowercase, Uppercase Letters?

Lowercase letter definition: Lowercase letters are all other letters not in uppercase.

Uppercase letter definition: Uppercase letters are letters that represent the beginning of a sentence or a proper noun.

What are Lowercase Letters?

In writing, most letters are lowercase. Lowercase letters are all letters that do not begin a sentence or refer to a proper noun.

English alphabet lowercase letters: a b c d e f g h i j k l m n o p q r s t u v w x y z.

Examples of Lowercase Letters:

  • word
  • The word above uses only lowercase letters.
  • The sentence above has lowercase letters after the first letter of the sentence.
  • This sentence and the one directly above have all lowercase letters except for the “T.”

What are Uppercase Letters?

Uppercase letters are also known as capital letters. Uppercase letters signal to the reader that something is important or significant.

English alphabet uppercase letters: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z.

Examples of Uppercase Letters:

  • Jones
    • This is a proper name, so the first letter of the title and the last name are capitalized
  • Main Street
    • This is a proper noun so the first letter of each word is capitalized

When to Use Uppercase Letters

In English, the first letter of every sentence is capitalized. The uppercase letter signals to the reader that a new sentence is beginning.

Other uses of uppercase letters are detailed below.

Titles

All titles are considered proper nouns and require capitalization.

Examples:

  • Miss Mabry
    • Incorrect: miss mabry
  • Mathers
    • Incorrect: mr. mathers
  • Madam Lockfield
    • Incorrect: madam lockfield
  • Lady Grace
    • Incorrect: lady grace
  • Janks
    • Incorect: mrs. janks

Acronyms

Acronyms are a type of abbreviation. Acronyms are words formed from other letters to make a new word. However, they require capital letters to signal to the reader that those letters stand for something and are not a word alone.

Examples:

  • NATO
    • North Atlantic Treaty Organization
  • UNICEF
    • United Nations International Children’s Emergency Fund
  • SCUBA
    • Self-contained underwater breathing apparatus

All Proper Nouns

All proper nouns need to be capitalized.

Examples:

  • We visited the Bowers Museum on Saturday.
    • Incorrect: We visited the bowers museum on Saturday.
  • I would like to tour the Eiffel Tower.
    • Incorrect: I would like to tour the eiffel tower.
  • Their names are Jake and Suzy.
    • Incorrect: Their names are jake and suzy.

When to Use Lowercase Letters

Use lowercase letters for all letters other than the first in a sentence, provided that there is no required use for uppercase letters in the sentence.

Examples:

  • Every word in this sentence other than the first word is written in lowercase.
  • The only words in this sentence that require uppercase letters are the proper nouns, London and Paris.

All nouns that are not proper nouns are called common nouns. All common nouns use lowercase letters (unless a common noun begins a sentence).

Examples:

  • tree
  • dog
  • bird
  • water
  • air
  • star
  • street
  • girl
  • baby

Summary

Define lowercase letters: lowercase letters are those letters used for common nouns and internal words.

Define uppercase letters: uppercase letters (also called capital letters) are those letters that signify the beginning of a sentence or a proper noun.

In summary,

  • Uppercase and lowercase letters refer to all letters used to compose the English language.
  • Uppercase letters are used to begin sentences and are also used for proper nouns.
  • Lowercase letters are all letters that do not begin sentences.

Contents

  • 1 What are Lowercase Letters?
  • 2 What are Uppercase Letters?
  • 3 When to Use Uppercase Letters
    • 3.1 Titles
    • 3.2 Acronyms
    • 3.3 All Proper Nouns
  • 4 When to Use Lowercase Letters
  • 5 Summary

The truth about character case that programmers need to know / Habr

At the North Bay Python conference in 2018, I gave a talk on usernames. Most of the information in the report was compiled by me over 12 years of maintaining django-registration. This experience gave me a lot more knowledge than I had planned to have on how complex "simple" things can be.

At the beginning of the report, I did mention that this would not be another exposé from the series of "misconceptions about X that programmers believe." You can find any number of such revelations. However, I don't like these articles. They list various things that are allegedly false, but very rarely explain why this is so, and what should be done instead. I suspect that people will simply read articles like this, congratulate themselves on this achievement, and then go on to find new and interesting ways to make mistakes not mentioned in these articles. It's because they didn't really understand the problems that these bugs give rise to.

Therefore, in my report, I tried to explain some of the problems as best as possible and explain how to solve them - I like this approach much more. One topic that I've only touched on in passing (it was just one slide and a couple of mentions on other slides) is the complexities that can be associated with character case. There is an official Correct Answer™ for the problem I was discussing - comparing case-insensitive identifiers - and in the talk I gave the best solution I know, using only the Python standard library.

However, I briefly mentioned the deeper complications with Unicode case, and I want to spend some time describing the details. This is interesting, and understanding this can help you make decisions when designing and writing code that processes text. Therefore, I offer you something opposite to the articles "misconceptions about X that programmers believe" - ​​"the truth that programmers should know."

One more thing: Unicode is full of terminology. In this article, I will mainly use the definitions of "upper case" and "lower case" because the Unicode standard uses these terms. If you like other terms, like lowercase/uppercase letters, that's fine. Also, I will often use the term "symbol", which some may consider incorrect. Yes, in Unicode the concept of "character" isn't always what people expect, so it's often best to avoid it by using other terms. However, in this article, I will use the term as it is used in Unicode, to describe an abstract entity about which claims can be made. When it matters, I will use more specific terms like "code point" for clarification.

There are more than two registers

Speakers of European languages ​​are accustomed to using case in their languages ​​to denote specific things. For example, in English [and Russian] we usually start sentences with an uppercase letter and most often continue with lowercase letters. Also, proper nouns start with uppercase letters, and many acronyms and abbreviations are written in uppercase.

And we usually think that there are only two registers. There is an "A" and there is an "a". One is in upper case, the other is in lower case, isn't it?

However, there are three cases in Unicode. There is an upper one, there is a lower one, and there is a title case [titlecase]. In English, this is how names are written. For example, Avengers: Infinity War. Usually, to do this, the first letter of each word is simply written in uppercase (and depending on different rules and styles, some words, such as articles, are not capitalized).

The Unicode standard gives this example of a capital case character: U+01F2 LATIN CAPITAL LETTER D WITH SMALL Z. It looks like this: Dz.

Such characters are sometimes required to handle the negative consequences of one of the early design decisions of the Unicode standard: compatibility with existing text encodings in both directions. It would be more convenient for Unicode to compose sequences using the standard's character combination capabilities. However, in many systems already in existence, space has already been allocated for ready-made sequences. For example, in the ISO-8859-1 ("latin-1") standard, the character "é" has a prepared form numbered 0xe9. In Unicode, it would be preferable to write this letter with a separate "e" and an accent mark. But to ensure full compatibility in both directions with existing encodings such as latin-1, Unicode also assigns code points for predefined characters. For example, U+00E9 LATIN SMALL LETTER E WITH ACUTE.

Although this character's code position is the same as its latin-1 byte value, don't rely on it. It is unlikely that the character encoding in Unicode will retain these positions. For example, in UTF-8 code position U+00E9written as the byte sequence 0xc3 0xa9.

And, of course, there are characters in already existing encodings that needed special treatment when using title case, which is why they were included in Unicode "as is". If you want to look at them, search your favorite Unicode database for characters in the Lt ("Letter, titlecase") category.

There are several ways to determine the register

The Unicode Standard (§4.2) lists three different definitions of case. Perhaps the choice of one of the three makes your programming language for you; otherwise, your choice will depend on the specific purpose. Here are the definitions:

  1. A character is uppercase if it belongs to the category Lu ("Letter, uppercase"), and lowercase if it belongs to the category Ll ("Letter, lowercase"). The standard recognizes the limitations of this definition: each specific character has to be attributed to only one of the categories. Because of this, many characters that "should be" in upper or lower case will not meet this requirement because they belong to some other category.
  2. The character is uppercase if it inherits the Uppercase property, and lowercase if it inherits the Lowercase property. It is a combination of defining one with other character properties, which may include case.
  3. A character is in uppercase if it does not change after a case mapping to uppercase has been applied to it. A character is in lowercase if, after applying a lowercase case mapping to it, it does not change. A rather general definition, however, it can also behave non-intuitively.

If you are working with a limited subset of characters (specifically, letters), then 1 definition may be enough for you. If your repertoire is broader - it includes characters that look like letters that are not letters, the 2nd definition may suit you. It is also recommended by the Unicode standard, §4.2:

Programmers manipulating Unicode strings should work with string functions such as isLowerCase (and its functional cousin toLowerCase) if they do not operate on character properties directly.

The function mentioned here is defined in §3.13 of the Unicode Standard. Formally, the 3rd definition uses the functions isLowerCase and isUpperCase from §3.13, defined in terms of fixed positions in toLowerCase and toUpperCase, respectively.

If your programming language has functions for checking or converting the case of strings or individual characters, it's worth looking into which of the definitions mentioned are used in the implementation. If you're wondering, Python's isupper() and islower() methods use the 2nd definition.

Cannot understand the case of a character by its appearance or name

By the appearance of many characters, you can understand what case they are in. For example, "A" is in upper case. This is clear from the name of the symbol: "LATIN CAPITAL LETTER A". However, sometimes this method does not work. Let's take the code position U+1D34. It looks like this: ᴴ. In Unicode, it's assigned a name: MODIFIER LETTER CAPITAL H. So it's in uppercase, right?

In fact, it inherits the Lowercase property, so by definition #2 it is in lower case, despite the fact that it visually resembles a capital H, and the name contains the word "CAPITAL".

Some characters have no case at all

Definition 135 in §3.13 of the Unicode Standard reads:

The character C is case-sensitive if and only if C has a Lowercase or Uppercase property, or the value of the General_Category parameter is Titlecase_Letter.

So a lot of Unicode characters - in fact, most of them - are caseless. Questions about their case do not make sense, and case changes do not affect them. However, we can get the answer to this question by definition #3.

Some characters behave as if they have multiple cases

It follows from this that if you use definition #3 and ask if an uncase character is in uppercase or lowercase, you will get the answer "yes".

The Unicode standard gives an example (Table 4-1, line 7) of the U+02BD MODIFIER LETTER REVERSED COMMA character (which looks like this: ʽ). It does not have the inherited Lowercase or Uppercase properties, and is not in the Lt category, so it is not case-sensitive. However, converting to upper case does not change it, and converting to lower case does not change it, so by definition 3 it answers yes to both questions: "Are you upper case?" and “are you lowercase?”

This seems like a lot of unnecessary confusion, but the point is that definition #3 works with any sequence of Unicode characters, and simplifies case conversion algorithms (caseless characters just turn into themselves).

Case dependent on context

You might think that if the Unicode case conversion tables cover all characters, then this conversion is simply a matter of finding the right place in the table. For example, the Unicode database says that U+0041 LATIN CAPITAL LETTER A will be U+0061 LATIN SMALL LETTER A in lowercase. Simple, right?

One example where this approach does not work is Greek. The character Σ—that is, U+03A3 GREEK CAPITAL LETTER SIGMA—is mapped to two different characters when converted to lowercase, depending on where it appears in the word. If it is at the end of a word, then it will be ς (U+03C2 GREEK SMALL LETTER FINAL SIGMA) in lower case. Anywhere else it will be σ (U+03C3 GREEK SMALL LETTER SIGMA).

This means that the register has no one-to-one or transitivity. Another example is ß (U+00DF LATIN SMALL LETTER SHARP S, or escet). In uppercase it would be "SS", although there is now another uppercase form of it (ẞ, U+1E9E LATIN CAPITAL LETTER SHARP S). And converting "SS" to lowercase results in "ss", so (using Unicode terminology for case conversion): toLowerCase(toUpperCase(ß)) != ß.

Locale-specific case

Different languages ​​have different case conversion rules. The most popular example: i (U+0069 LATIN SMALL LETTER I) and I (U+0049 LATIN CAPITAL LETTER I) are converted to each other in most locales - most, but not all. In the az and tr locales (Turkic), the uppercase i is İ (U+0130 LATIN CAPITAL LETTER I WITH DOT ABOVE) and the lowercase I is ı (U+0131 LATIN SMALL LETTER DOTLESS I). Sometimes the right notation really means the difference between life and death.

Unicode itself does not handle all possible case conversion rules for all locales. In the Unicode database, there are only general rules for converting all characters that are not dependent on the locale. Also there are special rules for some languages ​​and compound forms - Lithuanian, Turkic languages, some features of Greek. Everything else is not there. §3.13 of the standard mentions this and recommends introducing locale-specific conversion rules when necessary.

One example that will be familiar to English speakers is the title case of certain names. "o'brian" must be converted to "O'Brian" (not to "O'brian"). However, in this case, "it's" must be converted to "It's", and not to "It's". Another example that is not handled in Unicode is the Dutch character "ij", which, when converted to title case, must be converted to uppercase if it appears at the beginning of a word. Thus, a large bay in the Netherlands would be "IJsselmeer" in the title case, not "Ijsselmeer". Unicode has the characters IJ U+0132 LATIN CAPITAL LIGATURE IJ and ij U+0133 LATIN SMALL LIGATURE IJ if you need them. By default, case conversion converts them to each other (although Unicode normalization forms using compatibility equivalence will split them into two separate characters).

Case-insensitive comparison requires folded case conversion

Returning to the material presented in the report. The complexity of dealing with case in Unicode means that case-insensitive comparison cannot be done using the standard lowercase or uppercase conversion functions found in many programming languages. For such comparisons, Unicode has the concept of case folding, and §3.13 of the standard defines the toCaseFold and isCaseFolded functions.

You might think that folding to folded case is like casting to lowercase, but it's not. The Unicode standard warns that a folded-case string will not necessarily be in lowercase. The Cherokee language is given as an example - there, in a line that is in folded case, characters in upper case will also come across.

One of the slides in my report implements the recommendations of Unicode Technical Report #36 in Python as fully as possible. NFKC is normalized and then the casefold() method (only available in Python 3+) is called on the resulting string. Even so, some edge cases fall out, and this is not exactly what is recommended for comparing identifiers. First, the bad news: Python doesn't expose enough Unicode properties to filter out characters that aren't in XID_Start or XID_Continue, or characters that have the Default_Ignorable_Code_Point property. To my knowledge it does not support NFKC_Casefold mapping. It also lacks an easy way to use the modified NFKC UAX #31§5.1.

The good news is that most of these edge cases do not involve any real security risks posed by the characters in question. And case folding is in principle not defined as a normalization-preserving operation (hence the NFKC_Casefold mapping, which renormalizes to NFC after case folding). Generally, when comparing, you don't care if both strings are normalized after preprocessing. What you care about is whether the preprocessing is inconsistent, and whether it guarantees that only strings that "should" be different afterwards will be different afterwards. If this bothers you, you can manually renormalize after case addition.

Enough for now

This article, like the previous report, is not exhaustive, and it is hardly possible to fit all this material into a single post. I hope this has been a useful overview of the complexities associated with this topic and that you will find enough starting points in it to look for further information. Therefore, in principle, you can stop here.

Wouldn't it be naïve for me to hope that other people would stop writing exposés from the series of "misconceptions about X that programmers believe" and start writing articles like "the truth programmers should know"?

What is the uppercase character on the keyboard

The first thing that falls into the hands of a computer user is a keyboard and a mouse. The ability to use various functions with the help of these attributes allows you to quickly solve tasks. If you ask a beginner what upper case is, he will probably point to the keys located at the top. In fact, this is far from being the case.

Contents of the article

  • Understanding upper and lower case on the keyboard
  • Where is the uppercase
  • How to switch the case on the keyboard

What is the upper and lower case on the keyboard

These concepts have come down to us since the days of typewriters. When typing, the usual type of writing was performed in the standard position of the equipment, which was called the lower one, and capital letters were applied to the paper when the position of the printing rods was changed, by moving them to the upper position. It is this function that the keyboards of modern mobile and stationary printing devices are endowed with.

With the help of the “Shift” functional transfer button from one mode to another, the PC user can switch to uppercase or uppercase letters when writing texts, depending on the content requirements. At the same time, the numbers indicate punctuation marks or other symbols that are used when printing documents. In other words, upper case is a printing mode in which letters become uppercase and numbers change to symbols. The lower one is the usual image of numbers and letters.

Where is the uppercase

Two keys for switching from one print mode to another are located on the keyboard: one on the lower left, and the other on the right - also at the bottom. This is done for the convenience of fast typing. If the letter to be capitalized is on the right, then the left side is used. When switching, press simultaneously, first "Shift", and then the desired character. And when the desired character is located on the left - vice versa. If it is convenient for the user to press both keys with one hand, then he does just that, for example, to display a comma!

ATTENTION! Some mobile device keyboards may have only one "Shift" key. This is due to the compact size of office equipment.

The ease of use of the upper mode allows you to quickly switch the function of the desired symbol from one position to another. In addition, on the left, above the "Shift" button, there is a key labeled "Caps Lock", which has the same functionality, but a different principle of operation.

Keyboard shifting methods

When typing texts, two switching modes are used:

  • short-term;
  • long.

The first of the listed methods switches the keyboard only at the moment of pressing the "Shift" key. As soon as the user releases it, printing continues in the normal mode - in capital letters.

The second method allows, after pressing the "Caps Lock" button, to change to upper case and type capital letters until there is no need to use them. A separate keyboard indicator lights up when this mode is enabled and goes out only when the specified key is pressed again, which confirms the transition to capitalization.

IMPORTANT! When "Caps Lock" is on, using the "Shift" button will have the opposite effect: when pressed, normal characters, and when released, capital letters.

Long mode is used when writing headings or emphasizing article titles.

Having the ability to quickly change from one case to another allows PC users to easily type the required texts by quickly inserting the necessary characters and capital letters.

Learn more