レストランに行きませんか.-What is its translation into English?It says that in Japanese this type of questions have suggestion meaning.Its translation is like *Why don't we go to a restaurant?* But its sounds like normal question sentence than suggestion one.I am little bit confused :/
You can say both 行きませんか and 行きましょうか. Generally, 行きませんか is more like an invitation - the speaker wants the other person to go with them, but doesn't know whether or not the other person wants to go. 行きましょうか is used when the speaker is more certain that the other person wants to go (e.g. maybe it's already been decided), and more expresses something the speaker wants to do, rather than something the speaker wants someone else to do.