how's your grammar?

I came across a totally interesting question this week, what's the difference between an idiom and a proverb? The really interesting part is, I had no idea how to answer that, no clue.
After a bit of googling I think I found out, still not 100% sure on this though,but that's not really the point of this post.

Idiom
a group of words in a fixed order that have a particular meaning that is different from the meanings of each word understood on its own:

Proverb
a short sentence, etc., usually known by many people, stating something commonly experienced or giving advice

It's still a bit vague... But accorcing to these definitions, a proverb must be a SENTENCE while an idiom is just a phrase (a group of words)???

A proverb is a saying such that almost everybody knows and you understand easily what it means. For example "Necessity is the mother of invention" is a proverb.

An idiom is a phrase such that almost nobody knows why it means so. "Kick the bucket" is an idiom to mean "die". Do you understand why it means so?

The point is that I learned this at some point in my english grammar classes, as well as tautology, spoonerisms, and a host of other super interesting grammatical devices. However, I have forgotten this, most of it anyway. And that makes me sad, and thus shall I blog about it.

I would like to issue a challenge, that we all keep our eyes and ears open for cool grammatical happenings. Let's try re-learn some of the ish we learned in high-school.

Borg