main / mane are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
main: (noun) any very large body of (salt) water. (noun) a principal pipe in a system that distributes water or gas or electricity or that collects sewage. (adjective) of force; of the greatest possible intensity.
mane: (noun) long coarse hair growing from the crest of the animal's neck. (noun) growth of hair covering the scalp of a human being.
main: m·EY·n
mane: m·EY·n
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)