彼は先生に

he ... to the teacher / he is ... as a teacher

→ 彼

phrase Rare #24,094

he ... to the teacher / he is ... as a teacher 彼は means “he,” while に changes meaning according to the following verb: in 先生にいくつか質問をした, it marks the person being asked; in 先生に向いてない, it means “suited to being a teacher.” This is an incomplete phrase rather than a fixed expression.

JA: 彼は先生に本を渡した。

EN: He gave the book to the teacher.

彼は先生にいくつか質問をした。

He asked the teacher several questions.

彼は先生に向いてないように見える。

He doesn’t seem cut out to be a teacher.

彼は先生に謝るべきだと私は思う。

I think he should apologize to his teacher.

彼は先生に向いてない。

He's not cut out to be a teacher.

彼は先生に本を贈るつもりだ。

He intends to give his teacher a book as a gift.

彼は先生に丁寧におじぎをした。

He bowed politely to his teacher.