What is true about a limerick?
When writing them, you can use "poetic license"(breaking the rules of grammar to create a special effect) and make up new endings for words so that things that don't typically rhyme will seem to rhyme.
They are funny poems with a very strict form.
They are based on number of syllables and cause the poem to all have the same rhythm. Japanese verse of five lines with a strict number of syllables in each line.
They are a light, humorous, nonsensical verse of five lines.