Why don't we play mahjong tonight?
      Let's play mahjong tonight.
      Wouldn't it be a good idea to play mahjong tonight?
      How about mahjong tonight?
      What about playing mahjong tonight?

      If someone makes a suggestion and you accept it, you can say:
      (如果你接納別人的提議，你可以說：）

      I'd love to.
      That's a very good idea.
      Good idea.
      All right.
      I don't mind. (willing but not too keen.願意但不太熱衷)
      Yes, why not?
      How to say no to suggestions politely
      (怎樣禮貌地拒絕別人的提議)
      If you want to turn down a suggestion or invitation, it is important to do so politely. Notice the use of some words or phrases (e.g. well, I'm afraid, to be quite honest) to make what you say more acceptable. If possible, tell the other person why you can't accept the invitation or suggestion.

      (如果你想禮貌地拒絕別人的提議或邀請，就要留意用例如well, I'm afraid, to be quite honest 這一類字或片語，令你的說話更容易被人接納。如果可以的話，告訴別人為什麼你不能接納他的邀請或提議。）

      Suggestion: Why don't we play mahjong tonight?
      Response: Well, I'm afraid I'm rather busy tonight.
      Suggestion: Would you like to play mahjong tonight?
      Response: Well, to be quite honest, I'm not very keen on mahjong.
      Suggestion: How about playing mahjong tonight?
      Response: Oh, do you think we have time?

      Also, you can always respond to a suggestion with your own suggestion.
      (此外，你也可以提出自己的建議來回應別人的提議。)

      Suggestion: Let's play mahjong tonight?
      Response: I'm afraid I have to work tonight.
      Why don't you give John a call ? He should be free tonight .