Limerick---A kind of humorous verse of five lines, in which the first, second, and fifth lines rhyme with each other, and the third and fourth lines, which are shorter, form a rhymed couplet.

Sonnet--a poem, properly expressive of a single, complete thought, idea, or sentiment, of 14 lines, usually in iambic pentameter, with rhymes arranged according to one of certain definite schemes, being in the strict or Italian form divided into a major group of 8 lines (the octave) followed by a minor group of 6 lines (the sestet), and in a common English form into 3 quatrains followed by a couple.

A limerick is a five line poem, usually with a humorous subject, usually in a trochaic metre, rimed

AABBA

(the B lines are nearly always shortened, and regularly halflines):

There was a young lady from Deal
Who was totally lacking appeal;
"Though I try and I try.
I just can't hook a boy! ...more