そうです => That's right N5
Confirm
そうですか => I see, is that so? N5
Situation, case
ねばならない/ねばならぬ/ねば => have to do; must; should ~ N2
それでこそ => Such N3
Cause, reason
ね => isn't it? right? eh? N5
はどうですか => how about; how is N5
はどうですか => how about; how is N5
Doubt
それはそうと => anyway N2
お…ねがう => please do; could you please…; I ask of you to ~ N4
Respectful, humble
たらどうですか => why don't you; how about ~ N4
Invite and advise
のほうが...です => one is better than the other N5
Compare
すら/ですら => even ~ (with emphasis) N1