1

We use the Present Perfect tense to talk about past experiences when the exact time they happened is not important or not known. It connects the past to the present.

2

To form it, use the helper verb 'have' or 'has' plus the past participle of the main verb (often called Verb 3). For regular verbs, the past participle ends in '-ed', just like the past simple. For example, 'I have visited Paris.'

3

Irregular verbs have special past participles. 'See' becomes 'seen', 'go' becomes 'gone' or 'been', and 'eat' becomes 'eaten'. For example, 'She has eaten sushi.' We often use the words 'ever' in questions and 'never' in negative statements about experiences.