soot / suit 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. 👇
soot: (verb) coat with soot.
suit: (noun) a set of garments (usually including a jacket and trousers or skirt) for outerwear all of the same fabric and color. (noun) (slang) a businessman dressed in a business suit. (noun) a petition or appeal made to a person of superior status or rank. (noun) playing card in any of four sets of 13 cards in a pack; each set has its own symbol and color. (verb) be agreeable or acceptable to. (verb) be agreeable or acceptable.
soot: s·UH·t
suit: s·UW·t
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)