1. What has he seen?
2. Why have you eaten?
3. Why have you phoned?// Whom have you phoned?
4. When has she started?
5. What has he broken?
6. What have they decided?
7. When has James arrived?
P.S насколько мне изветсно, то с when надо ставить вопросы в past simple
7. When did James arrive?
4. When did he start?