Contractions in English: Full List, Apostrophe Rules and When to Avoid Them

A contraction is a shortened form of two words in which an apostrophe marks the missing letters: do not becomes don't, it is becomes it's, should have becomes should've. One test settles most doubts: if you can expand it into two words and the sentence still works, it needs the apostrophe. Use contractions in email, blogs and dialogue; avoid them in formal essays and legal text.

What is a contraction?

A contraction is one word made from two, with an apostrophe standing where letters were left out. In "I'm late", the apostrophe replaces the "a" of "am". In "they've left", it replaces the "ha" of "have". Contractions are normal in speech and in most everyday writing, and they are one of the quickest ways to make a text sound natural.

The one test for every apostrophe doubt

If you can expand the word into two words and the sentence still makes sense, it is a contraction and takes an apostrophe. If the expansion makes no sense, it is not a contraction.

Two limits to know. First, the test is for contractions only: the apostrophe in a noun possessive such as "the manager's office" does not stand for missing letters, so it will not expand ("the manager is office" is wrong, and that is correct, because it is not a contraction). Second, the test tells you whether an apostrophe is needed, not whether the contraction suits your reader, which is the subject of the formality section below.

Full list of common English contractions

Pronoun + verb

Verb + not

Other common forms

Two negatives are irregular. "Can't" drops more than the "o" of "not" (it stands for "cannot"), and "won't" does not look like "will not" at all, because it comes from an older form of "will". You do not need the history: learn both as fixed words.

The same 's can mean three different things

The ending 's causes most of the trouble, because it can be a contraction of "is", a contraction of "has", or a possessive.

• "She's a teacher." = she is.
• "She's taught here for ten years." = she has.
• "She's classroom is on the left." is wrong: the possessive is "her classroom", and a possessive pronoun never takes an apostrophe.
• "The teacher's classroom is on the left." is correct: a possessive noun.

In the same way, 'd can be "would" ("I'd go") or "had" ("I'd gone"). The word after it tells you which: "I'd go" is followed by a bare verb, "I'd gone" by a past participle. For noun possessives and plural apostrophes, see the apostrophe rules and possessive nouns guides.

Contractions that look like possessives

Four pairs account for a large share of apostrophe mistakes. Each has its own entry with the rule and example sentences, so this guide does not repeat them:

• its or it's
• your or you're
• their, there or they're
• whose or who's

The pattern is the same every time: the contraction has an apostrophe because letters are missing, and the possessive pronoun has none. Run the two-word test and the answer appears.

Should have, not "should of"

Because "should've" sounds like "should of", many people write it that way. "Should of", "could of", "would of" and "must of" are nonstandard: the word is the auxiliary verb "have". Write "should have" in full, or "should've" where a contraction is acceptable. The entry for should have or should of gives the details.

When contractions are fine

Contractions are a matter of register, not of correctness. They are standard in:

• Email and workplace chat to colleagues and clients you know ("We've received your order").
• Blog posts, newsletters, product copy and social media, where a conversational voice is the aim.
• Fiction and dialogue. Characters who never use contractions sound stiff or foreign, which is a choice a writer can make on purpose but should not make by accident.
• Speeches, scripts and presentations, which are written to be heard.

They are also the safer choice when you write for a general audience that reads quickly, such as a help page or an instruction sheet.

When to avoid contractions

Avoid or reduce contractions in:

• Academic essays, dissertations and journal articles. Many university writing centres and style guides advise writing out contractions in formal academic prose. Your module handbook or the guide your department names has the final word, so check it before you submit.
• Legal documents, contracts, terms and official notices, where each word is meant to be exact and the tone is deliberately formal.
• Formal letters to authorities, cover letters in conservative sectors, and applications, where the reader may expect full forms.
• Text that will be translated or read mostly by learners of English. Full forms are easier to parse, though common ones such as "don't" and "it's" are usually understood.

US and UK practice agree on the principle even where the guides differ in detail: the more formal the document and the more distant the reader, the fewer contractions. A reasonable middle path for business writing is to use common contractions in friendly messages and write them out in the first formal contact. The tone in writing guide covers that choice more broadly, and email etiquette applies it to messages.

Before and after: formal and informal versions

The same message can be pitched at two levels by opening or closing its contractions.

Informal (email to a colleague): "We've got the draft, and it's nearly ready. I'd like to send it on Friday, but we can't until legal's signed off. Let's check in tomorrow."

Formal (report to a committee): "The draft has been received and is nearly complete. It is intended to be sent on Friday, but this cannot happen until the legal team has approved it. A progress check is scheduled for tomorrow."

Informal (website help text): "Don't worry if you've forgotten your password. You'll get a link in a minute."

Formal (terms of service): "If the user has forgotten the password, a reset link will be sent to the registered address."

Notice that removing contractions is rarely enough on its own to make a text formal; the second versions also change the sentence structure and drop "we" and "let's". Contractions are one signal of register among several.

Common mistakes

A last point of placement: in negative contractions the apostrophe replaces the "o" of "not", so it comes between the "n" and the "t", never between the verb and the "n" ("does'nt" is wrong).

A short checklist

1. Can I expand the word to two words, and does the sentence still work? If yes, keep the apostrophe.
2. Is it a possessive pronoun (its, your, their, whose, hers, ours, theirs)? Then there is no apostrophe.
3. Is the apostrophe where the letters were removed?
4. Does my reader or my course expect full forms? If so, write them out.
5. Am I consistent? A paragraph that mixes "do not" and "don't" without a reason looks accidental.

Using AdeptWrite to check contractions

The Grammar Checker checks grammar, spelling and punctuation and shows each change so you can accept or reject it; it is useful for catching a stray "its" or "your" in a long draft, but read the suggestions yourself, because only you know the register you intend. The Spell Checker checks against American, British, Australian or Canadian English word lists and flags unknown spellings, such as "dont". To turn a casual draft into a formal one, or the reverse, the Tone Changer offers Formal, Office and Casual modes; review the result, as a tool cannot know your course rules or house style.

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