5) If he (goes/went/had gone/would go) to London yesterday, he (met/would meet/had met/would have met) his old friend. 6) I will lend them some money if they (ask/will ask/asked/had asked) me. 7) If we had known who he was, we (would have invited/have invited/will invite/would invite) him to speak at our meeting. 8) My dog will bark if it (hear/hears/heard/had heard) any strange sound. 9) If I (had/had had/will have/have) enough money, I would buy a house. 10) They (won’t let/not let/wouldn’t let/hadn’t let) you in if you come late. 11) If you (not go/don’t go/hadn’t gone/didn’t go) away, I’ll send for a policeman. 12) If I (were/am/be/was) in your place, I would accept Mr. Anderson’s invitation. 13) If I (win/had won/won/winning) a big prize in a lottery, I’d give up my job. 14) If I (is/am/was/were) you, I (will tell/told/would tell/would have told) the truth. 15) I was busy. If I (have/had/had had/have had) free time. I (would go/will go/would have gone/go) to the cinema with you. Giúp mìk vs ạ!