Top 10 Differences between American English and British English

1) Pronunciation.
2) Spelling (o v. ou, s v. z).
3) Formal and notional agreement.
4) Verb Endings and the treatment of irregular verbs.
5) Presence or absence of syntactic elements.
6) Prepositions and adverbs.
7) Vocabulary (flashlight v. torch, rubbish v. trash).
8) Building Floors are numbered differently - For Americans, the 1st Floor is the floor you enter on, while for British, the 1st Floor is one up from the Ground Floor.
9) Punctuation - Americans tend to use more punctuation in writing than Brits.
10)


3) Formal and notional agreement

In BrE, collective nouns can take either singular (formal agreement) or plural (notional agreement) verb forms, according to whether the emphasis is, respectively, on the body as a whole or on the individual members; compare a committee was appointed... with the committee were unable to agree....56 Compare also the following lines of Elvis Costello's song "Oliver's Army": Oliver's Army are on their way / Oliver's Army is here to stay. Some of these nouns, for example staff,7 actually combine with plural verbs most of the time.

In AmE, collective nouns are usually singular in construction: the committee was unable to agree... AmE however may use plural pronouns in agreement with collective nouns: the team takes their seats, rather than the team takes its seats. The rule of thumb is that a group acting as a unit is considered singular and a group of "individuals acting separately" is considered plural.8 However, such a sentence would most likely be recast as the team members take their seats. Despite exceptions such as usage in the New York Times, the names of sports teams are usually treated as plurals even if the form of the name is singular.9

The difference occurs for all nouns of multitude, both general terms such as team and company and proper nouns (for example, where a place name is used to refer to a sports team). For instance,

BrE: The Clash are a well-known band; AmE: The Clash is a well-known band. BrE: New York are the champions; AmE: New York is the champion.

Proper nouns that are plural in form take a plural verb in both AmE and BrE; for example, The Beatles are a well-known band; The Giants are the champions.

4) Verbs

Verb morphology
* The past tense and past participle of the verbs learn, spoil, spell (only in the word-related sense), burn, dream, smell, spill, leap, and others, can be either irregular (learnt, spoilt, etc.) or regular (learned, spoiled, etc.). In BrE, the irregular and regular forms are current; in some cases (smelt, leapt) there is a strong tendency towards the irregular forms (especially by speakers using Received Pronunciation); in other cases (dreamed, leaned, learned10) the regular forms are somewhat more common. In AmE, the irregular forms are never or rarely used (except for burnt and leapt).
Nonetheless, as with other usages considered nowadays to be typically British, the t endings are often found in older American texts. However, usage may vary when the past participles are actually adjectives, as in burnt toast. (Note that the two-syllable form learnèd /'lɜːnɪd/, usually written simply as learned, is still used as an adjective to mean "educated", or to refer to academic institutions, in both BrE and AmE.) Finally, the past tense and past participle of dwell and kneel are more commonly dwelt and knelt on both sides of the Atlantic, although dwelled and kneeled are widely used in the US (but not in the UK).
* Lit as the past tense of light is much more common than lighted in the UK; the regular form enjoys more use in the US, although it is somewhat less common than lit. By contrast, fit as the past tense of fit is much more used in AmE than BrE, which generally favors fitted.
* The past tense of spit "expectorate" is spat in BrE, spit or spat in AmE.
* The past participle of saw is normally sawn in BrE and sawed in AmE (as in sawn-off/sawed-off shotgun).


* The past participle gotten is rarely used in modern BrE (although it is used in some dialects), which generally uses got, except in old expressions such as ill-gotten gains. According to the Compact Oxford English Dictionary, "The form gotten is not used in British English but is very common in North American English, though even there it is often regarded as non-standard." In AmE, gotten emphasizes the action of acquiring and got tends to indicate simple possession (for example, Have you gotten it? versus Have you got it?). Gotten is also typically used in AmE as the past participle for phrasal verbs using get, such as get off, get on, get into, get up, and get around: If you hadn't gotten up so late, you might not have gotten into this mess. Interestingly, AmE, but not BrE, has forgot as a less common alternative to forgotten for the past participle of forget.
* In BrE, the past participle proved is strongly preferred to proven; in AmE, proven is now about as common as proved. (Both dialects use proven as an adjective, and in formulas such as not proven).
* AmE further allows other irregular verbs, such as dive (dove) or sneak (snuck), and often mixes the preterit and past participle forms (spring–sprang, US also sprung–sprung), sometimes forcing verbs such as shrink (shrank–shrunk) to have a further form, thus shrunk–shrunken. These uses are often considered nonstandard; the AP Stylebook in AmE treats some irregular verbs as colloquialisms, insisting on the regular forms for the past tense of dive, plead and sneak. Dove and snuck are usually considered nonstandard in Britain, although dove exists in some British dialects and snuck is occasionally found in British speech.
* By extension of the irregular verb pattern, verbs with irregular preterits in some variants of colloquial AmE also have a separate past participle, for example, "to buy": past tense bought spawns boughten. Such formations are highly irregular from speaker to speaker, or even within idiolects. This phenomenon is found chiefly in the northern US and other areas where immigrants of German descent are predominant, and may have developed as a result of German influence (though in German, both are regular past participle forms, cf. kaufen, kaufte, gekauft (bought) and lesen, las, gelesen (read)). Even in areas where the feature predominates, however, it has not gained widespread acceptance as "standard" usage.

Use of tenses

* BrE uses the present perfect tense to talk about an event in the recent past and with the words already, just, and yet. In American usage, these meanings can be expressed with the present perfect (to express a fact) or the simple past (to imply an expectation). This American style has become widespread only in the past 20 to 30 years; the British style is still in common use as well.
o "I've just arrived home." / "I just arrived home."
o "I've already eaten." / "I already ate."


(Recently the American use of just with simple past has made inroads into BrE, most visibly in advertising slogans and headlines such as "Cable broadband just got faster".)

* Similarly, AmE occasionally replaces the pluperfect with the preterite. Also, US spoken usage sometimes, especially with the contracted forms, substitutes the conditional for the pluperfect (If I would have cooked the pie we could have had it for lunch),citation needed but this tends to be avoided in writing.
* In BrE, have got or have can be used for possession and have got to and have to can be used for the modal of necessity. The forms that include ‘‘got’’ are usually used in informal contexts and the forms without got in contexts that are more formal. In American speech the form without got is used more than in the UK, although the form with got is often used for emphasis.


Colloquial AmE informally uses got as a verb for these meanings – for example, I got two cars, I got to go.


* The subjunctive mood (morphologically identical with the bare infinitive) is regularly used in AmE in mandative clauses (as in They suggested that he apply for the job). In BrE, this usage declined in the 20th century, in favor of constructions such as They suggested that he should apply for the job (or even, more ambiguously, They suggested that he applied for the job). Apparently, however, the mandative subjunctive has recently started to come back into use in BrE.


Verbal auxiliaries

* Shall (as opposed to will) is more commonly used by the British than by Americans. Shan't is seldom used in AmE (almost invariably replaced by won't or am not going to), and very much less so amongst Britons. American grammar also tends to ignore some traditional distinctions between should and would22; however, expressions like I should be happy are rather formal even in BrE.
* The periphrastic future (be going to) is about twice as frequent in AmE as in BrE.

Transitivity

The following verbs show differences in transitivity between BrE and AmE.

* agree: Transitive or intransitive in BrE, usually intransitive in AmE (agree a contract/agree to or on a contract). However, in formal AmE legal writing one often sees constructions like as may be agreed between the parties (rather than as may be agreed upon between the parties).
* appeal (as a decision): Usually intransitive in BrE (used with against) and transitive in AmE (appeal against the decision to the Court/appeal the decision to the Court).
* catch up ("to reach and overtake"): Transitive or intransitive in BrE, strictly intransitive in AmE (to catch sb up/to catch up with sb). A transitive form does exist in AmE, but has a different meaning: to catch sb up means that the subject will help the object catch up, rather the opposite of the BrE transitive meaning. In other words, the subject acts more like an indirect object.
* cater ("to provide food and service"): Intransitive in BrE, transitive in AmE (to cater for a banquet/to cater a banquet).
* claim: Sometimes intransitive in BrE (used with for), strictly transitive in AmE.
* meet: AmE uses intransitively meet followed by with to mean "to have a meeting with", as for business purposes (Yesterday we met with the CEO), and reserves transitive meet for the meanings "to be introduced to" (I want you to meet the CEO; she is such a fine lady), "to come together with (someone, somewhere)" (Meet the CEO at the train station), and "to have a casual encounter with". BrE uses transitive meet also to mean "to have a meeting with"; the construction meet with, which actually dates back to Middle English, appears to be coming back into use in Britain, despite some commentators who preferred to avoid confusion with meet with meaning "receive, undergo" (the proposal was met with disapproval). The construction meet up with (as in to meet up with someone), which originated in the US,25 has long been standard in both dialects.
* provide: Strictly monotransitive in BrE, monotransitive or ditransitive in AmE (provide sb with sth/provide sb sth).
* protest: In sense "oppose", intransitive in BrE, transitive in AmE (The workers protested the decision/The workers protested against the decision). The intransitive protest against in AmE means, "to hold or participate in a demonstration against". The older sense "proclaim" is always transitive (protest one's innocence).
* write: In BrE, the indirect object of this verb usually requires the preposition to, for example, I'll write to my MP or I'll write to her (although it is not required in some situations, for example when an indirect object pronoun comes before a direct object noun, for example, I'll write her a letter). In AmE, write can be used monotransitively (I'll write my congressman; I'll write him).


Complementation

* The verbs prevent and stop can be found in two different constructions: "prevent/stop someone from doing something" and "prevent/stop someone doing something". The latter is well established in BrE, but not in AmE.
* Some verbs can take either a to+infinitive construction or a gerund construction (e.g., to start to do something/doing something). For example, the gerund is more common:
o In AmE than BrE, with start, begin, omit, enjoy;
o In BrE than AmE, with love, like, intend.


5) Presence or absence of syntactic elements

* Where a statement of intention involves two separate activities, it is acceptable for speakers of AmE to use to go plus bare infinitive. Speakers of BrE would instead use to go and plus bare infinitive. Thus, where a speaker of AmE might say I'll go take a bath, BrE speakers would say I'll go and have a bath. (Both can also use the form to go to instead to suggest that the action may fail, as in He went to take/have a bath, but the bath was full of children.) Similarly, to come plus bare infinitive is acceptable to speakers of AmE, where speakers of BrE would instead use to come and plus bare infinitive. Thus, where a speaker of AmE might say come see what I bought, BrE speakers would say come and see what I've bought (notice the present perfect tense: a common British preference).
* Use of prepositions before days denoted by a single word. Where British people would say She resigned on Thursday, Americans often say She resigned Thursday, but both forms are common in American usage. Occasionally, the preposition is also absent when referring to months: I'll be here December (although this usage is generally limited to colloquial speech).
* In the UK, from is used with single dates and times more often than in the United States. Where British speakers and writers may say the new museum will be open from Tuesday, Americans most likely say the new museum will be open starting Tuesday. (This difference does not apply to phrases of the pattern from A to B, which are used in both BrE and AmE.) A variation or alternative of this is the mostly American the play opens Tuesday and the mostly British the play opens on Tuesday.
* American legislators and lawyers always use the preposition of between the name of a legislative act and the year it was passed, while their British colleagues do not. Compare Americans with Disabilities Act of 1990 to Disability Discrimination Act 1995.


The definite article

* A few 'institutional' nouns take no definite article when a certain role is implied: for example, at sea (as a sailor), in prison (as a convict), and at/in college (for students). Among this group, BrE has in hospital (as a patient) and at university (as a student), where AmE requires in the hospital and at the university. (When the implied roles of patient or student do not apply, the definite article is used in both dialects.)
* Likewise, BrE distinguishes in future ("from now on") from in the future ("at some future time"); AmE uses in the future for both senses.
* AmE omits, and BrE requires, the definite article in a few standard expressionsclarify such as tell (the) time.
* In BrE, numbered highways usually take the definite article (for example "the M25", "the A14") while in America they usually do not ("I-495", "Route 66"). Southern California is an exception, where "the 5" or "the 405" are the standard. A similar pattern is followed for named roads, but in America, there are local variations and older American highways tend to follow the British pattern ("the Boston Post Road").
* AmE distinguishes in back of behind from in the back of; the former is unknown in the UK and liable to misinterpretation as the latter. Both, however, distinguish in front of from in the front of.
* Dates usually include a definite article in UK spoken English, such as "the eleventh of July", or "July the eleventh", while American speakers say "July eleventh".


6) Prepositions and adverbs * In the United States, the word through can mean "up to and including" as in Monday through Friday. In the UK Monday to Friday, or Monday to Friday inclusive is used instead; Monday through to Friday is also sometimes used. (In some parts of Northern England the term while can be used in the same way, as in Monday while Friday, whereas in Northern Irelandcitation needed Monday till Friday would be more natural.)
* British athletes play in a team; American athletes play on a team. (Both may play for a particular team.)
* In AmE, the use of the function word out as a preposition in out the door and out the window is standard. In BrE, out of is preferred in writing, but out is more common in speech. Several other uses of out of are peculiarly British (out of all recognition, out of the team; cf. above); all of this notwithstanding, out of is overall more frequent in AmE than in BrE (about four times as frequent, according to Algeo).
* The word heat meaning "mating season" is used with on in the UK and with in in the US.
* The intransitive verb affiliate can take either with or to in BrE, but only with in AmE.
* The verb enrol(l) usually takes on in BrE and in in AmE (as in "to enrol(l) on/in a course") and the on/in difference is used when enrolled is dropped (as in "I am (enrolled) on the course that studies....").
* In AmE, one always speaks of the street on which an address is located, whereas in BrE in can also be used in some contexts. In suggests an address on a city street, so a service station (or a tourist attraction or indeed a village) would always be on a major road, but a department store might be in Oxford Street. Moreover, if a particular place on the street is specified then the preposition used is whichever is idiomatic to the place, thus "at the end of Churchill Road", and thus also the lyric "our house, in the middle of our street" from "Our House" by the British band Madness, whose intended meaning is "halfway along our street" but is confusing to many Americans—in AmE, the lyric suggests that the house is literally in the middle of the roadway.
* BrE favours the preposition at with weekend ("at (the) weekend(s)"); the constructions on, over, and during (the) weekend(s) are found in both varieties but are all more common in AmE than BrE.36 See also Word derivation and compounds.
* Adding at to the end of a question requesting a location is common in AmE (especially in the Midwest), for example, "where are you at?", but would be considered superfluous in BrE.
* After talk American can use the preposition with but British alwayscitation needed uses to (that is, I'll talk with Dave / I'll talk to Dave. The American form is sometimes seen as more politically correct in British organisations, inducing the ideal of discussing (with), as opposed to lecturing (to). This is, of course, unless talk is being used as a noun, for example: "I'll have a talk with him" in which case this is acceptable in both BrE and AmE.
* In both dialects, from is the preposition prescribed for use after the word different: American English is different from British English in several respects. However, different than is also commonly heard in the US, and is often considered standard when followed by a clause (American English is different than it used to be), whereas different to is the alternative common in BrE.
* It is common in BrE to say opposite to as an alternative to opposite of, the only form normally found in AmE. The use of opposite as a preposition (opposite the post office) has long been established in both dialects, but appears to be more common in British usage.
* The noun opportunity can be followed by a verb in two different ways: opportunity plus to-infinitive ("the opportunity to do something") or opportunity plus of plus gerund ("the opportunity of doing something"). The first construction is the most common in both dialects, but the second has almost disappeared in AmE and is often regarded as a Briticism.
* Both British and Americans may say (for example) that a river is named after a state, but "named for a state" would rightly be regarded as an Americanism.
* BrE sometimes uses to with near (we live near to the university), while AmE avoids the preposition in most usages dealing with literal, physical proximity (we live near the university), although the to reappears in AmE when near takes the comparative or superlative form, as in she lives nearer/nearest to the deranged axe murderer's house.
* In BrE, one calls (or rings) someone on his or her telephone number; in AmE, one calls someone at his or her telephone number. * When referring to the constituency of a US Senator the preposition "from" is usually used: "Senator from New York," whereas British MPs are "for" their constituency: "MP for East Cleveland."
* In AmE, the phrases aside from and apart from are used about equally; in BrE, apart from is far more common.


Phrasal verbs * In the US, forms are usually but not invariably filled out, but in Britain they can also be filled in. However, in reference to individual parts of a form, Americans may also use in (fill in the blanks). In AmE the direction fill it all in (referring to the form as a collection of blanks, perhaps) is as common as fill it all out.
* Britons facing extortionate prices may have no option but to fork out, whereas Americans are more likely to fork (it) over or sometimes up; both usages are however found in both dialects.
* In both countries, thugs will beat up their victim; AmE also allows beat on (as both would for an inanimate object, such as a drum) or beat up on, which are often considered slang.
* When an outdoor event is postponed or interrupted by rain, it is rained off in the UK and rained out in the US.


7) Vocabulary
Words mainly used in British English

Some speakers of AmE are aware of some BrE terms, such as lorry, queue, chap, bloke, loo, and shag, although they would not generally use them, or may be confused as to whether someone intends the American or British meaning (such as for biscuit). They will be able to guess approximately what some others, such as “driving licence”, mean. However, use of many other British words such as naff (unstylish, though commonly used to mean "not very good"), risks rendering a sentence incomprehensible to most Americans.

Words mainly used in American English

Speakers of BrE are likely to understand most AmE terms, examples such as sidewalk, gas (gasoline/petrol), counterclockwise or elevator (lift), without any problem although they would generally not use them. Terms which are heard less frequently in the UK, such as semi (articulated lorry), stroller (pram/pushchair) or kitty-corner/catty-corner (diagonally opposite) are highly unlikely to be understood by most BrE speakers.

Words with different meanings

Words such as bill (AmE "paper money", BrE and AmE "invoice") and biscuit (AmE: BrE's "scone", BrE: AmE's "cookie") are used regularly in both AmE and BrE, but mean different things in each form. As chronicled by Winston Churchill, the opposite meanings of the verb to table created a misunderstanding during a meeting of the Allied forces;citation needed in BrE to table an item on an agenda means to open it up for discussion, whereas in AmE, it means to remove it from discussion.

9) Punctuation

* Full stops/Periods in abbreviations: Americans tend to write Mr., Mrs., St., Dr. etc., while British will most often write Mr, Mrs, St, Dr, etc, following the rule that a full stop is used only when the last letter of the abbreviation is not the last letter of the complete word; this kind of abbreviation is known as a contraction in the UK. Many British writers would tend to write other abbreviations without a full stop, such as Prof, etc, eg, and so forth (as recommended by OED). The 'American' usage of periods after most abbreviations can also be found in the UK although publications generally tend to eschew the extreme use of punctuation found in US publications. Unit symbols such as kg and Hz are never punctuated.
* It is sometimes believedcitation needed that BrE does not hyphenate multiple-word adjectives (e.g. "a first class ticket"). The most common form is as in AmE ("a first-class ticket"), but some British writers omit the hyphen when no ambiguity would arise.
* Quoting: Americans start with double quotation marks (") and use single quotation marks (') for quotations within quotations. This can also occur in BrE,citation needed but is most often the opposite in more formal circumstances such book publishing. In journals and newspapers, quotation mark double/single use depends on the individual publication's house style.
* Contents of quotations: Americans are taught to put commas and periods inside quotation marks (except for question marks and exclamation points that apply to a sentence as a whole), whereas British people will put the punctuation inside if it belongs to the quotation and outside otherwise.
o Carefree means "free from care or anxiety." (American style)
o Carefree means "free from care or anxiety". (British style)


The American style was established for typographical reasons, a historical holdover from the days of the handset printing press. It also eliminates the need to decide whether a period or comma belongs to the quotation. However, many people find the usage counterintuitive. Hart's Rules and the Oxford Dictionary for Writers and Editors call the British style "new" or "logical" quoting; it is similar to the use of quotation marks in many other languages (including Portuguese, Spanish, French, Italian, Catalan, Dutch, and German). For this reason, the more "logical" British style is increasingly used in America, although formal writing still generally calls for the "American" style. In fact, the British style is often the de facto standard among Americans for whom formal or professional writing is not a part of their daily life; many are in fact unaware that the normative American usage is to place commas and periods within the quotation marks.citation needed (This rule of placing all punctuation inside quotation if and only if it belongs to the quotation is expressly prescribed by some American professional organizations such as the American Chemical Society; see ACS Style Guide.) According to the Jargon File, American hackers have switched to using "logical" British quotation system, because including extraneous punctuation in a quotation can sometimes change the fundamental meaning of the quotation. More generally, it is difficult for computer manuals, online instructions, and other textual media to accurately quote exactly what a computer user should see or type on their computer if they follow American punctuation conventions.
In both countries, the "British" style is used for quotation around parentheses, so in both nations one would write:

"I am going to the store. (I hope it is still open.)"

But:

"I am going to the store (if it is still open)."

* Letter-writing: American students in some areas have been taught to write a colon after the greeting in business letters ("Dear Sir:") while British people usually write a comma ("Dear Sir,") or make use of the so-called open punctuation ("Dear Sir"). However, this practice is not consistent throughout the United Statescitation needed, and it would be regarded as a highly formal usage by most Americans.