Use of the Present Perfect
In British English the present perfect is used to express an action that has happened in the recent past that has an effect on the present moment. For example:
I've lost my key.
In American English the following is also possible:
I lost my key.
In British English the second variant should be considered in correct.
However, both forms are generally accepted in standard American English.
The Verb Get
The past participle of the verb get is gotten in American English. ‘For example:
He's gotten much better at playing tennis.
British English - He's got much better at playing tennis.
Past Simple/Past Participles
The following verbs have two acceptable forms of the past simple/past participle in both American and British English, however, the irregular form is generally more common in British English and the regular form is more common to American English. (Infinitive is the same)
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