seito wa sensei no setsumei ga wakariyasui to omoimasu.

topic particle

Breakdown of seito wa sensei no setsumei ga wakariyasui to omoimasu.

• 先せん生せい: teacher
• が: subject particle
• の: possessive case particle

Questions & Answers about seito wa sensei no setsumei ga wakariyasui to omoimasu.

In this sentence, who is actually doing the thinking – the students or the speaker?

Grammatically, the one doing the thinking is the speaker (the person saying the sentence), not the students.

• 生徒は marks 生徒 as the topic: “As for the students / speaking about the students…”
• 〜と思います normally means “I think that 〜” (the subject I is just omitted).

So the most natural interpretation is:

• “(I) think that the teacher’s explanation is easy to understand for the students.”

If you really want to say “The students think …”, you would usually make 生徒 clearly the subject of 思う, for example:

• 生徒は先生の説明が分かりやすいと思っています。
  “The students think that the teacher’s explanation is easy to understand.”

The original sentence is more about the speaker’s opinion, from the students’ point of view.

Why does 生徒 use は, and 説明 use が?

This is a very common pattern in Japanese:

N1 は N2 が A (adjective)

It often means:

• “For N1, N2 is A.”

Here:

• 生徒は – topic / “as for the students / for the students”
• 先生の説明が – grammatical subject of the adjective
• 分かりやすい – “easy to understand”

So:

• 生徒は先生の説明が分かりやすい。
  “For the students, the teacher’s explanation is easy to understand.”

Then 〜と思います just adds “I think …” to that.

So:

• は: marks the overall topic / viewpoint (the group we are talking about).
• が: marks the thing that is actually easy to understand (the explanation).