You look tired.
疲れているようだね
You lucky [silly] thing!
ラッキーなやつだ［このバカたれが］
You may as well have dinner with us.
一緒に夕食を食べませんか（◆主語が二人称だと提案を表す）
You may have a trust that people will be driving carefully, but don't trust them.
人は慎重に運転すると思いがちだが，当てにはできない
You may have it for the asking.
ただですよ
You may rest assured of his success.
彼はきっとうまくやりますから安心してください
you may well ask
((略式))（わけを）聞いてみたいもんだね
You may well be right.
おそらく君は正しいだろう
You may well believe it.
君がそれを信じるのももっともだ
You might as well expect a river to flow backward as hope to move me.
私の心を動かそうとするのは川の逆流を期待するようなものだ
