American vs. British English: Spelling, Words, and Grammar

American and British English are the same language with different house rules. A reader in Chicago and a reader in London will both understand “colour,” “lift,” and “at the weekend,” but each will notice when you’ve switched teams.

For most writing, the goal isn’t to master both. It’s to pick one variety and stick to it. This guide walks through the differences you’re most likely to run into, with American English as the home base, since that’s what GrammarVista.com USA teaches.

You’ll find spelling patterns first (the biggest source of inconsistency), then vocabulary, grammar, punctuation, and dates, plus the settings that keep your spell-checker on your side.

Spelling Patterns: The Big Six

Most American spellings come from a few predictable patterns. Learn the pattern and you’ve learned hundreds of words.

Notes on the patterns

• -ize vs. -ise: American English uses -ize. British English accepts both, and Oxford University Press famously prefers -ize. Some words end in -ise everywhere: advertise, exercise, surprise, compromise, supervise.
• -er vs. -re: A few words keep -re in American English too: acre, massacre, mediocre, ogre. You’ll also see “Theatre” in the names of some US venues; that’s branding, not standard spelling.
• -ense vs. -ence: In British English, licence and practice are nouns, while license and practise are verbs. American English uses license and practice for both.
• -og vs. -ogue: Americans write catalog and analog, but dialogue is still the usual American spelling for conversation. Dialog shows up mainly in software (“dialog box”).

Quick rule: If a word ends in -our, -re, or -ise and you’re writing for Americans, check whether it has a shorter US form.

Doubled Letters and One-Off Spellings

The doubled L

When adding -ed, -ing, or -er to a verb ending in l, British English doubles the l even when the stress isn’t on the last syllable. American English usually doesn’t.

But watch the reversal: American English often uses two l’s where British uses one.

• 🇺🇸 enroll, fulfill, skillful, installment
• 🇬🇧 enrol, fulfil, skilful, instalment

You’ll still see cancellation (double l) in American English, even though canceled has one. Merriam-Webster lists both canceled and cancelled; canceled is the more common US form.

Words to memorize

Memory trick: Gray is American; grey is English.

Vocabulary: Same Thing, Different Word

Spelling differences rarely cause confusion. Vocabulary differences can, especially when the same word means different things.

False friends

These words exist in both varieties but don’t mean the same thing:

• Pants: In the US, trousers. In the UK, underwear.
• First floor: In the US, the floor at street level. In the UK, that’s the ground floor, and the first floor is one level up.
• Biscuit: In the US, a soft, bread-like side dish. In the UK, a cookie or cracker.
• Holiday: Americans use it for specific days (Thanksgiving, July 4) and vacation for time off. Brits use holiday for both.

Grammar Differences

The grammar gap is smaller than the vocabulary gap, but a few patterns stand out.

Collective nouns

American English treats most collective nouns as singular. British English often treats them as plural when the focus is on the members.

• 🇺🇸 The team is playing well. The government has announced a plan.
• 🇬🇧 The team are playing well. The government have announced a plan.

Band and company names follow the same pattern: an American writes “Apple is releasing,” while a Brit may write “Apple are releasing.” Our grammar rules guide covers agreement in more depth.

Got vs. gotten

American English uses gotten as a past participle of get when it means “obtained” or “become.” It uses got for possession (have got).

• 🇺🇸 She’s gotten much better at chess. (improved)
• 🇺🇸 I’ve got two tickets. (I have two tickets.)
• 🇬🇧 She’s got much better at chess.

Present perfect

British English tends to use the present perfect for recent actions with just, already, and yet. American English accepts the present perfect, but the simple past is common and fully standard, especially in speech.

• 🇬🇧 I’ve just eaten. Have you finished yet?
• 🇺🇸 I just ate. Did you finish yet? (Both forms are correct in the US.)

Prepositions

Different from is safe everywhere. Different than is common and accepted in American English, especially before a clause (The city is different than I remember). Different to reads as British.

Shall

In American English, shall is mostly limited to legal and formal documents (The tenant shall pay rent monthly) and polite suggestions (Shall we go?). For the future tense, Americans use will.

Punctuation Differences

Quotation marks

This is the punctuation difference American readers notice most.

• American: Use double quotation marks, with single marks for a quote inside a quote. Periods and commas always go inside the closing quotation mark.
• British: Single quotation marks are common, and punctuation usually goes inside only if it belongs to the quoted material.

🇺🇸 She called the plan “ambitious,” but she said it would “probably work.”

🇬🇧 She called the plan ‘ambitious’, but she said it would ‘probably work’.

In American style, colons and semicolons go outside the quotation marks. Question marks and exclamation points go inside only if they belong to the quote: He asked, “Are you ready?” but Did she really say “no”?

Abbreviated titles

American English puts a period after Mr., Mrs., Ms., and Dr. British English usually drops the period when the abbreviation ends with the word’s last letter: Mr Smith, Dr Patel.

The serial comma

The serial (Oxford) comma is the comma before and in a list of three or more: red, white, and blue. The Chicago Manual of Style recommends it, and it’s common in American books and academic writing. AP style, used by most US newsrooms, omits it unless needed for clarity. British usage is mixed but generally leaves it out. Read more in our post on the Oxford comma and our full punctuation guide.

Dates, Times, and Numbers

Dates

In American running text, put a comma after the year when the date falls mid-sentence: On October 16, 2026, the office will close early.

Quick rule: For international readers, spell out the month. “03/04/2026” could be March 4 or April 3; “March 4, 2026” can’t be misread.

Times

Americans usually use the 12-hour clock with a.m. and p.m. (lowercase with periods in AP and Chicago style): The meeting starts at 9:30 a.m. The 24-hour clock (“military time”) is mostly used in the military, hospitals, and some technical fields. British writing uses both the 12-hour and 24-hour clocks and often writes the time with a period: 9.30am.

Numbers and measurements

• “And” in numbers: Americans often say “one hundred five”; Brits say “one hundred and five.” Both are understood.
• Units: The US uses customary units (miles, pounds, Fahrenheit). The UK uses metric for most things but still uses miles for road distances and pints for beer and milk.
• Decimals and thousands: Both use a period for decimals and a comma for thousands: $1,250.75.

How to Choose and Stay Consistent

Neither variety is “more correct.” What looks careless is mixing them in one document, like color in paragraph one and colour in paragraph three.

1. Pick based on your audience. Writing for US customers, schools, or employers? Use American English. Publishing in the UK? Use British.
2. Follow your organization’s style guide. If your company uses AP or Chicago, you’re using American conventions.
3. Don’t “correct” quotations or proper nouns. Keep Royal Opera House and Pearl Harbor as they’re officially spelled.
4. Watch the sneaky ones. Spelling is easy to catch. Quotation punctuation, collective nouns, and dates are where mixed styles slip through.
5. Keep word choice consistent too. Don’t write apartment and flat in the same piece.

The same principle applies to tricky word pairs like toward/towards; see our tricky words guide for more.

Setting Your Spell-Checker to American English

Your spell-checker can only help if it knows which variety you’re using.

Microsoft Word

1. Select all text (Ctrl+A on Windows, Cmd+A on Mac).
2. Go to Review > Language > Set Proofing Language (on some versions: Language > Language Preferences).
3. Choose English (United States).
4. To make it the default for new documents, click Set As Default.

Google Docs

1. Go to File > Language.
2. Choose English (United States).

Spelling suggestions in Google Docs follow the document language, so set it once per document. If you paste text from a British source, re-check the language setting for the pasted section in Word, since pasted text can bring its own language tag.

Quick Checklist

• Spelling: -or, -er, -ize, -yze, -ense, single l in traveled.
• One-offs: gray, check, tire, aluminum, program.
• Vocabulary: apartment, elevator, fall, vacation, sidewalk.
• Grammar: Singular collective nouns (the team is), gotten, on the weekend.
• Quotes: Double quotation marks; periods and commas inside.
• Titles: Mr., Mrs., Dr. with periods.
• Dates: October 16, 2026, with a comma after the year mid-sentence.
• Settings: Document language set to English (United States).
• Consistency: One variety per document, start to finish.