An English Quintain is a poem that consists of five lines hence the "quint" in quintain. A quintain does not have a specific length for each line. It can be as short or as long as the poet likes. The rhyme scheme of an English quintain is a/b/a/b/b. The most well-known and common form of quintains is actually a limerick.
A quintain is beautiful in its simplicity and is most enjoyed by the humor in limericks, but it does not have a specific theme that needs to be followed. A quintain can be romantic, dramatic, as well as humorous. THere is no limit to what topic a quintain can be used to write.
This is much more popular form of Quintet having no set measure or foot and has a rhyming scheme of a. b. a. b. b.