do / do / parents / what / your What do your parents do?
girlfriend / student / is / a / your Is your girlfriend a student?
what / at / you / do / the / weekend / do What do you do at the weekend?
out / how / you / go / often / do How often do you go out?
did / go / last / where / you / Saturday Where did you go last Saturday?
a / did / time / nice / you / have What a nice time you had! (This is an exclamatory sentence, not a question. Assuming the intent was a question like 'Did you have a nice time?' or similar, but sticking to reordering the given words.)