An example of an impersonal verb in English is 'one has' or 'one goes'. Use the pronoun se and the he/she form of a verb to form an impersonal verb. Impersonal verbs in English include verbs such as ...

You use the perfect tense when, in English, you would say that something has happened. So, if you wanted to say: ‘You have been to the hairdresser,' 'she has eaten all the biscuits’ or anything else ...