help的形容詞副詞是？

Is he really helpful?

他真的有用嗎？

I'm helpful at home.

我在家很有用。

I'm helpful.

我是有用的。

Let me explain!' he added helpfully.

“讓我來説明一下！”他熱心地補充道。

He gave his name and then helpfully spelled it.

他説出了他的'名字，然後又熱心地把它拼讀了出來。

She helpfully suggested that I try the local library.

她很熱心地建議我試試本地的圖書館。