simonsez“"I enjoy watching t.v." The word watching is used as a subject noun (i.e. a gerund) and the word t.v. is what?”
watching is not a subject noun, no. The underlying structure is
I enjoy [ I watch TV]. The bracketed part is the object of the verb enjoy.
The clause I watch TV when expressed as a gerund construction becomes my watching TV. That is, the subject becomes a possessive adjective, and the verb becomes a gerund. (The rest stays the same. TV is still the direct object of watch.)
When the main clause and the gerund clause share the same subject, you delete the subject of the gerund construction (my), leaving
I enjoy watching TV. (Not I enjoy my watching TV.)
Compare:
I like collecting stamps.
He hates writing letters.
But when the main clause and gerund clause do not share the same subject:
Peter objects to my watching TV.
CJ