她是谁，我不认识她。

I know not who she is.

和谁啊？我不认识她。

Who? I don't know her.

我认识她的两个大儿子，但我不认识她最小的儿子。

I know her two elder sons, but I don't know the youngest one.

我发誓我不认识她。

I don't know her， I promise.

我不认识她。我只是感觉到我迫切的希望为她做些什么。

I did not know who she was; I just felt that I urgently had to do something for her.