II. Put the verbs in brackets into the Present Perfect or Past Simple or Present Perfect Continuous. 1. Why ______ (you/not go) to the party last night? 2. ______ (we/know) each other for a long time. 3. Jim ______ (Jim/play) the piano since he was 10.

II. Using Present Perfect, Past Simple, or Present Perfect Continuous:

1. Why didn't you go to the party last night? (Past Simple for a specific past action).
2. We have known each other for a long time. (Present Perfect Continuous or Present Perfect for an action that started in the past and continues to the present).
3. Jim has been playing the piano since he was 10. (Present Perfect Continuous for an action that started in the past and continues to the present, emphasizing duration).

Note: For question 2, 'have known' (Present Perfect) is also acceptable and often preferred when focusing on the state of knowing.