Chen (work) in Singapore, since he (leave) university.
has been working/left
Maria (come round) to dinner last night.She (start) telling me her life story, while I(make) the salad and (continue) telling it during dinner.
came/started/making/continued
I (grow up) in a house, which (belong) to my great-great-grandfather. We (sell) it now, because it was too big for our small family.
grew/belonged/have sold
Alexamder takes university life very seriously. He(study) here for six months and still (not go) to a single party.
has been studying/hasn't been
Ivana (have) a splitting headache yesterday evening, because she (work) in the sun all day and she (not wear) a hat.
had/had been working/hadn't been wearing