Tautology!

This is a linguistic feature that can bug me quite abit.

It is essentially when a term contains different words that mean the same thing.

For instance, why do people use the term "Advance warning"? There is no such thing as a retroactive warning; that would constitute gloating. Saying that the warning is in advance is redundant, since that's the only type of warning!

The worst type of tautology, however, is when people say things like "The cheapest price" or "The fastest speed".

A price can be high or low, it cannot be cheap! Cheap means "Has a low price", if the price is cheap then it means that the price has a low price. That's nonsensical!

I would write more, but I don't seem able to. It's really quite disconcerting, the way in which my brain isn't functioning today. It might have something to do with my changes in daily rhythm, but I can't shake the feeling that I might be going slightly mad...