The document defines and explains the present perfect tense in English grammar. It notes that the present perfect expresses an action that began in the past and continues into the present. It is formed using has/have plus the past participle. Examples of its use include actions that occurred at an indefinite time in the past or with time expressions like ever, never, yet, and already. The document provides the forms for affirmative, interrogative, and negative constructions in both short and long forms for regular and irregular verbs.

7. Present Perfect Have they travelled? They've travelled They have travelled Have you travelled? You've travelled You have travelled Have we travelled? We've travelled We have travelled Has it travelled? It's travelled It has travelled Has she travelled? She's travelled She has travelled Has he travelled? He's travelled He has travelled Have you travelled? You've travelled You have travelled Have I travelled? I've travelled I have travelled Short Form Long Form Interrogative Affirmative

8. You haven't travelled You have not travelled We haven't travelled We have not travelled It hasn't travelled It has not travelled She hasn't travelled She has not travelled He hasn't travelled He has not travelled You haven't travelled You have not travelled I haven't travelled I have not travelled Short Form Long Form Negative

9. Irregular Verbs They haven't bought Have they bought? They've bought You haven't bought Have you bought? You've bought We haven't bought Have we bought? We've bought It hasn't bought Has it bought? It's bought She hasn't bought Has she bought? She's bought He hasn't bought Has he bought? He's bought You haven't bought Have you bought? You've bought I haven't bought Have I bought? I've bought Negative Interrogative Affirmative