1. Houses in the city are much more expensive than those in the countryside. (cheap)
-> Houses in the countryside are cheaper than those in the city.
2. Lan is not allowed to go out alone at night. (NOT)
-> Lan is not permitted  to go out alone at night.
3. Sebastien is French, but he plays Vietnamese folk games well. (although)
-> Sebastien plays Vietnamese folk games well, although he is French.
4. I failed the quiz in math; therefore, I have to stay for tutoring. (BECAUSE)
->I have to stay for tutoring because I failed the quiz in math
5. You should come I failed the quiz in math, or you cannot join the procession.
-> If you come to the festival early, you can join the procession.