You can get me in the office on Monday.
月曜なら私は会社にいます
You can stick this job if you don't give me decent wages.
まともな賃金を払わないならだれがこんな仕事を引き受けるか
You don't have to come if you don't want to.
いやなら来なくていいよ（◆否定形は不必要を表す）
You may go if you wish.
行きたいのなら行ってもよい
You may go out on condition (that) you (should) return before sunset.
日没前に帰るなら外出してもよい
You may go with him if you (so) choose.
行きたいのなら彼といっしょに行ってもいいよ
You must have finished your report by next March.
君は来年の３月までにレポートを仕上げなければならない．
You must know yourself.
人はおのれ自身を知らねばならない
You must look to your health.
健康に注意しなければならない
You must needs [needs must] do your duty.
義務をはたさねばならぬ
