sail / sale 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. 👇
sail: (noun) a large piece of fabric (usually canvas fabric) by means of which wind is used to propel a sailing vessel. (noun) any structure that resembles a sail. (verb) traverse or travel on (a body of water). (verb) travel on water propelled by wind.
sale: (noun) a particular instance of selling. (noun) the general activity of selling. (noun) an occasion (usually brief) for buying at specially reduced prices. (noun) the state of being purchasable; offered or exhibited for selling. (noun) an agreement (or contract) in which property is transferred from the seller (vendor) to the buyer (vendee) for a fixed price in money (paid or agreed to be paid by the buyer).
sail: s·EY·l
sale: s·EY·l
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)