10. when it ( rain )., they ( walk).through the forest. 11. I ( not/see)..her since 2002, but I often ( write ) to her every weekend. 12. She ( finish) her report since Monday. 13. It ( not/rain).here for a long times. 14. They ( not/ go)..to the movies together for ages. 15. Sorry! I (not/ write)..to you for a long times. 16. My mother ( watch ).that film three times, 17. How long have you ( learn )English? 18. This is the worst restaurant they ( eat/ever) 19. That is the first time he ( meet)a beautiful girl such her. 20. He ( work)in this company since he ( leave).high school.

`10.` Rained/ Were walking

`->` When + S + Ved, S + was/were + Ving

`11.` Haven't seen/ Write

`->` Since là DHNB của HTHT : S + have/has + not + P2.

`->` Often là DHNB của HTĐ : S + V(s/es) + O.

`12.` Has finished

`->` Since là DHNB của HTHT : S + have/has + P2.

`13.` Hasn't rained

`->` For là DHNB của HTHT : S + have/has + not + P2.

`14.` Haven't gone

`->` For là DHNB của HTHT : S + have/has + not + P2.

`15.` Haven't written

`->` For là DHNB của HTHT : S + have/has + not + P2.

`16.` Has watched

`->` Three times là DHNB của HTHT : S + have/has + not + P2.

`17.` Learnt

`->` How long have/has + S + P2 : Bao lâu

`18.`Have ever eaten

`->` This is the + adj-est/most adj + S + have/has + (ever) + P2.

`19.` Has met

`->` This is the first time S + have/has + (ever) + P2.

`20.` Has worked/ Left

`->` S + have/has + P2 + since + S + Ved