1. Shall we go to the cinema tonight?
-> What about going to the cinema tonight?
-> Why don't we go to the cinema tonight?
-> Let's go to the cinema tonight
2. Why don't we use gas instead of burning coal?
-> I suggest using gas instead of burning coal
-> How about using gas instead of burning coal ?
-> Shall we use gas instead of burning coal?
3. How about reducing the amount of water we use everyday?
-> Why don't we reduce the amount of water we use everyday?
-> Let's reduce the amount of water we use everyday
-> Shall we reduce the amount of water we use everyday?
4. What about using energy-saving appliances?
-> I think we should use energy - saving appliances
-> Shall we use energy - saving appliances?
-> Why don't we use energy - saving appliances?