Grammar differences

The grammars of American and British English are basically quite similar, but here

The grammars of American and British English are basically quite similar, but here
are some important ways in which American English differs from British English:
The past forms of some verbs
In American English some irregular verbs can have a form of the past simple
or past participle that is not used in British English.
He dived / (US also) dove into the pool.
Jake has got / (US usually) gotten really fat.
The past simple
In many situations where British English uses the present perfect form of the
verb, American English uses the past simple:
UK US
I think I’ve lost my camera. I think I lost my camera.
Thanks, but I’ve already eaten. Thanks, but I already ate.
Different prepositions
UK US
The shop is open from Monday The shop is open Monday
to Saturday. through Saturday.
It’s a quarter past seven. It’s a quarter after seven.
Differences in spelling
In American English,words tend to be spelt more simply or more like the way they
are pronounced. Compare the following British and American spellings:
UK US UK US
equalled equaled litre liter
plough plow honour honor
Australian English usually follows British spellings, although there are some
American spellings that are also acceptable.