Noun Clause which Began With Question Words

A clause is a group of related words. It contains a subject and a verb.
A noun clause is a dependent which cannot stand alone as a sentence. It must be connected to an independent clause  (a main clause). The following  question words can be used to introduce a noun clause : what, where, when, why, how, who, whom, which, whose.
A noun clause can be used as a subject or an object.

Examples :

Subject	Verb	Object
I	enjoy	It
I	Enjoy	What I do
It	confuses	Me
What he says	confuses	Me