Summary: Prefixes are key morphemes in English vocabulary that begin words. The prefix *sub-*, with its variants which all begin with *su-*, is a prolific part of the English language. Examples using this prefix include [*sub*]way, [*suf*]fer, [*sup*]ply, and [*sug*]gest. An easy way to remember that the prefix *sub-* means "under" is through the word [*sub*]marine, or a vehicle that travels "under" the sea.
