Perscriptive vs. Descriptive Limericks

The following are some limericks to explain the difference between perscriptivism and descriptivism in linguistics.

“The Perscriptivist”

There once was a perscriptive linguist
who thought that he knew grammar things best.
    “Don’t say that,” he said,
    “use this phrase instead.”
Come on, man, just give it a rest!

“The Descriptivist”

There once was a descriptive linguist
who researched what grammar trends exist.
    “We say this,” he said,
    “But we could say that instead.
It all just depends on the context.”

“Ain’t”

If you say the word “ain’t” every day,
a perscriptivist would say “no way!”
    But as long as it could
    be readily understood
a descriptivist says it’s okay.