sensei wa gakusei ni jugyou no kansou o kikimashita.

The teacher asked the students for their impressions of the class.

Breakdown of sensei wa gakusei ni jugyou no kansou o kikimashita.

• は: topic particle
• 学がく生せい: student
• を: direct object particle

Questions & Answers about sensei wa gakusei ni jugyou no kansou o kikimashita.

What is the role of the particle は after 先生, and could we use が instead?

は marks 先生 as the topic of the sentence: “As for the teacher, …”. It sets what we are talking about.

You could use 先生が instead. Then 先生 is emphasized more as the subject that performed the action, often in contrast to someone else (e.g. “It was the teacher (not someone else) who asked…”).

So:

• 先生は学生に授業の感想を聞きました。 – Neutral “The teacher asked the students…”
• 先生が学生に授業の感想を聞きました。 – Focus on the teacher as the doer, useful in contrastive contexts.

Why is 学生 marked with に instead of を?

With the verb 聞く, when it means “to ask (someone)”, the person you ask is marked with に, and the thing you ask about is marked with を.

Pattern: [person] に [thing] を 聞く

So in this sentence:

• 学生に – “to the student(s)” (the person being asked)
• 授業の感想を – “the impressions of the class” (what is being asked for)

If you used 学生を, it would suggest the students themselves are the direct object (which doesn’t fit with this meaning of 聞く).

What does 授業の感想 literally mean, and how does の work here?