who?

[Sokheang Thea]

I don't know who is talking to her.
I don't know the person who is talking to her.which one is correct?

Where she went is none of your own business. correct?

[jupiter]

Hi Sokheang

I don't know who is talking to her.
I don't know the person who is talking to her.which one is correct?

Where she went is none of your own business. correct?

"I don't know who is talking to her." is correct because "who is talikng to her" is noun clause which is the object of the verb "know".
"I don't know the person who is talking to her" is also correct because "who is talking to her" is an adjective clause that modifies the noun "person". And "the person who is talking to her" is the object of the verb "know".

"Where she went is none of your business" is absolutely correct because "where she went" is a noun clause that functions as a subject of the sentence.

Any comment is appreciated

Jupiter

[vutha_cupid]

You're right. I give you a thumb.

[Sokheang Thea]

thank you both! It just confuses me.