Is but a conjunction

Answer 1

Yes, the word 'but' is one of the 7 coordinating conjuctions in the English language. They are used to join words, phrases or clauses. The other 6 are: for, and, nor, or, yet, so they are the fanboys
Yes, the word 'but' is a conjunction, a preposition, an adverb, and a noun.

EXAMPLES:

I never win, but I keep trying. (conjunction)

All but three students passed the test. (preposition)

He is but a simple fellow. (adverb)

I'm listening to your excuse. I'm waiting for the but. (noun)

Answer 2

Yes, "but" can be used as a conjunction to indicate a contrast or exception in a sentence. It is often used to connect two contrasting ideas or clauses together.

Answer 3

YES