relative pronoun VS relative adverb

[hela]

Dear teachers,

To which category these underlined words belong?
Which category these underlined words belong to?
(which stce is best?)

a) I don't know what to do.
b) I don't know how to do it.
c) I don't know who that man is.

Many thanks,
Hela

[Tdol]

I'd say a&c are pronouns and b might be debated as to whether it is an adverb or a conjunction. I'd o for the latter.

[Wai_Wai]

For b)
There's 1 clear sentence (without any combination of sub-sentences). "How" here does not connect any sentences, so it is adverb.

(compare:
She described to me how he ran up to her and grabbed her handbag.
Here the first sub-sentence is She described to me. Second one is he ran up to her and grabbed her handbag