学校の成績が

school grades

→ 学校
phrase Rare #26,972
school grades The particle が marks school grades as the subject, and the phrase is usually followed by a description such as いい (good) or 悪い (bad).
JA: 学校の成績がいいです。
EN: My school grades are good.

その子は学校の成績が良い。

That child gets good grades at school.

彼は学校の成績がいい。

He gets good grades at school.

彼が学校の成績がよいのはまったく当然だ。

It’s only natural that he gets good grades at school.

親は学校の成績が良ければ子供を誇りに思う。

Parents are proud of their children when they get good grades at school.

学校の成績が悪いと仕事を探す時に不利だ。

Poor grades at school can put you at a disadvantage when looking for a job.

彼女は学校の成績が良かったはずがない。

She couldn't possibly have gotten good grades in school.

僕は学校の成績が上がったよ。

My grades at school have improved.