There are quite a few noticeable differences between the British English dialect and the evolved dialect of American English.

These are the aspects we will cover:SpellingPronunciation {sounds}GrammarVocabulary

AMERICAN – “-or”

BRITISH – “-our”

Color Colour

Honor Honour

Favorite favourite

AMERICAN – “-ll”

BRITISH – “-l”

Enrollment Enrolment

Fulfill Fulfil

Skillful skilful

AMERICAN – “-ze”

BRITISH – “-se”

Analyze Analyse

Criticize Criticise

Memorize Memorise

AMERICAN – “-er”

BRITISH – “-re”

Center Centre

Meter Metre

Theater theatre

AMERICAN – “-og”

BRITISH – “-ogue”

Analog Analogue

Catalog Catalogue

Dialog Dialogue

AMERICAN – “-ck” or “-k”

BRITISH – “-que”

Bank Banque

Check Cheque

AMERICAN – “-e” BRITISH – “-ae” or “-oe”

Encyclopedia Encyclopaedia

Maneuver Manoeuvre

Medieval Mediaeval

AMERICAN – “-dg” “-g” “-gu”

BRITISH – “-dge” “-ge” “-gue”

Aging Ageing

Argument Arguement

Judgment Judgement

AMERICAN – “-ense”

BRITISH – “-ence”

License Licence

Defense Defence

AMERICAN BRITISH

Jewelry Jewellry

Draft Draught

Pajamas Pyjamas

Plow Plough

Program Programme

Tire Tyre

Other word-specific differences --

BASE WORD

AMERICAN BRITISH

Counsel Counseling Counselling

Equal Equaled Equalled

Model Modeling Modelling

Quarrel Quarreling Quarrelling

Signal Signaled Signalled

Travel Traveling Travelling

Base words that end in L normally double the L in British English when a suffix is added.

The letter can double in American as well – but ONLY IF the stress is on the second syllableof the base word.

BASE WORD

AMERICAN

BRITISH

Excel Excelling Excelling

Propel Propelling Propelling

WORD AMERICAN PRONUNCIATION

BRITISH PRONUNCIATION

Teacher

Father

Letter

Water

Aunt

Tomato

There are also other words borrowed from French that feature stress differences.

American first-syllable; British last-syllable:

Mustache MustacheCigarette Cigarette

NOUNSIn British English, collective nouns

can take either singular or plural verb forms, depending on whether the emphasis is on the body or the members within it.

i.e.“A committee was appointed.” “ The committee were unable

to agree.”

VERBSmorphology American -- "-ed" British -- "-t" i.e. learned/learnt, dreamed/dreamt British English rarely use “gotten;” instead, “got” is much more common. Past participles often vary: i.e. saw – American: sawed; British: sawn

tenses British English employs the present perfect to talk about a recent event {i.e. “I’ve already eaten,” “I’ve just arrived home.”}

auxiliaries British English often uses “shall” and “shan’t” American English uses “will” and “won’t”

American& BritishEnglishsometimeshavedifferentwords forthe samethings --

AMERICAN BRITISH

Apartment Flat

Argument Row

Carriage/coach Pram

Bathroom Loo

Can Tin

Cookie Biscuit

Diaper Nappy

Elevator Lift

Eraser Rubber

Flashlight Torch

Fries Chips

Gas Petrol

Guy Bloke/chap

AMERICAN BRITISH

Highway Motorway

Hood {of a car} Bonnet

Jelly Jam

Kerosene Paraffin

Lawyer Solicitor

Line Queue

Mail Post

Napkin Serviette

Nothing Nought

Period Full stop

Potato chips crisps

AMERICAN BRITISH

Truck Lorry

Trunk Boot

Vacation Holiday

Windshield Windscreen

License Plate Number Plate

Pacifier Dummy

Parking lot Car park

Pharmacist Chemist

Sidewalk Pavement

Soccer Football

Trash can Bin

American and British English speakers often use the same words but intend very different meaning with them:WORD AMERICAN BRITISH

Biscuit Dinner roll Cookie

Brew Beer Tea

Bureau Chest of drawers Writing table/desk

Casket Coffin Jewelry Box

First Floor Ground Floor “Second” Floor

To hire To employ To rent

http://en.wikipedia.org/wiki/List_of_words_having_different_meanings_in_British_and_American_English {for more examples!}