3 walk 4 How well does your friend speak...? speaks 5 What language did he learn...? learnt 6 What language is he learning..? is learning 7 How long does your class usually last? lasts 8 How long did your class last...? lasted 9 Who did you discuss this question....? discussed 10 Who do you usually go...? go 11 How well does he usually know..? 12 didn't work 13 Are you working...? 14 How long did you stay...? stayed ...How long are you going to stay..? I'm going to stay...