そんな風に振る舞うとは彼は頭がおかしいにちがいない。の英語

To behave like that, he must be out of his mind.

He must be crazy to behave like that.

He must be crazy to do such a thing.

He must be a fool to do such a thing.

He must be joking, or else he's mad.

It's shameful that he behaves that way.

He must be crazy that he should do so.

He must be crazy to say such a thing.

Is he mad that he should say such a foolish thing?

I can't understand why he should do such a thing.

He must be crazy to say such a thing.

He must be crazy to say such a thing.

Once he is bent on anything, nothing can turn him from it.

He must be a fool to talk like that.

He's intelligent, but I still don't like him.

That he should behave like this!

It was foolish of him to do such a thing.

He doesn't behave himself once he's drunk.

Granted his cleverness, he may still be mistaken.

He's obdurate in his convictions.

He must be crazy to talk like that.

He must be crazy to say such a thing.

He will probably say that I'm insane.

It'll take a lot to make him change his mind.

He must be crazy to treat his parents like this.

You're a real optimist if you expect him to compromise on such terms.

His mind must be addled.

He may be clever, but he is not very helpful.

He must be mad to say such things.

I wouldn't put it past him to play a trick like that.