For written English, there is not much difference in British and American English except that the Americans have improvised it whereever they could to look different. Ex. If in British English u hire a Taxi, u hire a cab in USA. I shall give u a few more examples.
    British English:( See the difference in the use of tense)Riya is not at home. She has gone shopping.
    American English: Riya isn't at home; she went for shopping.
    In British English, the correct present perfect tense has been used but the Americans have improvised to their convenience and made it past indefinite tense. Here r some more examples for u to study in vocabulary especially.
    British English American English
    at the weekend on the weekend
    live in X street live on X street
    a player in the team a player on the team
    Monday to Thursday Monday through Thursday
    ten minutes past six ten minutes after six
    five minutes to ten five minutes of ten
    analyse analyze
    cheque check (money)
    centre center
    colour color
    defence defense
    dialogue dialog
    honour honor
    jeweller jeweler
    programme programe
    metre meter
    realise realize
    skilful skilfull
    theatre theater
    traveller traveler
    Aeroplane Airplane
    angry mad
    anywhere anyplace
    biscuit cookie/cracker
    There r numerous examples with me which distinguish between British English and American Emglish. In accent, the use of the vowel a is made 90% as in ash, bash. In British English there are twenty vowels(speech sounds) but in American English there r only five speech sounds. This is how they have made English more easy, useful and practical. U may post ur specific queries and I shall try to give u the best answer to the best of my ability.