Question

how does American english differ from British english write a good essay with evidences and lines

Answer 1

Speakers of American English generally use the present perfect tense (have/has + past participle) far less than speakers of British English. In spoken American English, it is very common to use the simple past tense as an alternative in situations where the present perfect would usually have been used in British English. The two situations where this is especially likely are: 

1. In sentences which talk about an action in the past that has an effect in the present:

American English (AmE) / British English (BrE)

Jenny feels ill. She ate too much. (AmE)Jenny feels ill. She's eaten too much. (BrE)I can't find my keys. Did you see them anywhere? (AmE)I can't find my keys. Have you seen them anywhere? (BrE)

2. In sentences which contain the words already, just or yet:

American English / British English

A: Are they going to the show tonight? B: No. They already saw it. (AmE)A: Are they going to the show tonight?B: No. They've already seen it. (BrE)A: Is Samantha here?B: No, she just left. (AmE)A: Is Samantha here?B: No, she's just left. (BrE)A: Can I borrow your book?B: No, I didn't read it yet. (AmE)A: Can I borrow your book?B: No, I haven't read it yet. (BrE)Verb agreement with collective nouns

In British English, collective nouns,(i.e. nouns referring to particular groups of people or things), (e.g. staff, government, class, team) can be followed by a singular or plural verb depending on whether the group is thought of as one idea, or as many individuals, e.g.

My team is winning.The other team are all sitting down.

In American English, collective nouns are always followed by a singular verb, so an American would usually say:

Which team is losing?

whereas in British English both plural and singular forms of the verb are possible, as in:

Which team is/are losing?