1. Helen speaks French so well because she (to live) in France. 2. She (to live) there last year.

1. Helen speaks French so well because she has lived in France. (Present Perfect, так как есть результат в настоящем). 2. She lived there last year. (Past Simple, так как указано конкретное время). 3. The rain has stopped and the sun is shining in the sky again. (Present Perfect, результат — светит солнце). 4. The rain stopped half an hour ago. (Past Simple, указано время). 5. Mary has bought a new hat. (Present Perfect, результат). 6. I bought a pair of gloves yesterday. (Past Simple, указано время). 7. The wind has blown off the man's hat, and he cannot catch it. (Present Perfect, результат — он не может ее поймать). 8. The weather has changed, and we can go for a walk. (Present Perfect, результат — мы можем идти). 9. The wind changed in the morning. (Past Simple, указано время). 10. We traveled around Europe last year. (Past Simple, указано время). 11. My father knows so much because he has traveled a lot. (Present Perfect, результат — он много знает). 12. I have seen Pete today. (Present Perfect, сегодня — это еще не закончившийся период). 13. She saw this film last Sunday. (Past Simple, указано время). 14. Alex met his friend two hours ago. (Past Simple, указано время). 15. I have just met our teacher. (Present Perfect, маркер just). 16. The children have already decided what to do with the books. (Present Perfect, маркер already). 17. Yesterday they decided to help their grandmother. (Past Simple, указано время). 18. I haven't seen you for a long time. I saw you in town two or three days ago, but you didn't see me. I was on a bus. (Первое предложение — Present Perfect, период for a long time. Дальше идет Past Simple, так как есть указание времени ago).