[MMM]

何 can be read なん or なに

りんごが好きなんです. This なん has nothing to do with 何.

This is the ~んです form used with nouns and な adjectives. so な＋んです.

いきたいんです。たべたいんです。好きなんです。

All the same forms...

なんで means "why"

なんとか is a filler word meaning "something" when, for example, you can't think of the right word or name.

"What was that robot movie called again? "なんとか・E"?

And all grammar goes out the window with music.