Is it a hypothesis or an hypothesis?

Answer:
Either works, given the often-contrary nature of the English usage of H.

However, I've heard "a hypothesis" more than "an hypothesis".

Improved Answered:

In instances where words that begin with "h" use the consonant sound..."a" is used.

So the proper form is "a hypothesis". See the official rules for a or an at the link below.
First answer by 3u8rbba98edy2. Last edit by Informyou. Contributor trust: 2 [recommend contributor recommended]. Question popularity: 2 [recommend question].