彼は英語では

as for his English

→ 彼
phrase Rare #31,753
as for his English Used to compare someone's ability or performance specifically in English, often with a contrastive nuance: “as far as his English is concerned.”
JA: 彼は英語では妹よりずっと上手だ。
EN: As far as his English is concerned, he is much better than me.

彼は英語ではより優れている

He is better than me at English.

彼は英語ではクラスのより進んでいる

He is ahead of his classmates in English.

彼は英語では私たちより勝っている

He is better than us at English.

彼は英語ではわたしよりずっと劣っている

He is far inferior to me in English.

彼は英語では私達より進んでいる

His English is more advanced than ours.

彼は英語では私たちのクラスのより進んでいる

He is ahead of everyone else in our class in English.