彼の成功は

his success

→ 彼
phrase Rare #21,208
his success は marks the topic; English often leaves it untranslated, though it can mean “as for.”
JA: 彼の成功はみんなの励みになった。
EN: His success inspired everyone.

彼の成功は、彼の勤勉の結果から生じた。

His success was the result of his hard work.

彼の成功はいくらかは運がよかったためだ。

His success was partly due to good luck.

彼の成功は両親のおかげです。

His success is thanks to his parents.

彼の成功は努力の賜物だと彼女は言った。

She said that his success was the result of his hard work.

彼の成功は努力次第だ。

His success depends on his efforts.

彼の成功は大部分幸運によるものだった。

His success was largely due to luck.

彼の成功は疑いない。

His success is beyond doubt.

彼の成功は私にとって大きな喜びでした。

His success was a great joy to me.

我々は彼の成功は、勤勉のためであると思う。

We believe his success is due to his hard work.

私たちは彼の成功は、勤勉のためだと思います。

We think his success is due to his hard work.