To avoid annoying grammar geeks, make sure you know where your prepositions are at.

An extremely controversial rule in grammar is that you should never end a sentence with a preposition. In a lot of cases, it is actually more reasonable to end a sentence with a preposition, but in the case of “Where is he at” or “Where is it at,” the ‘at’ is unnecessary and may be considered bad grammar, so the above sentence addresses this issue whilst breaking the rule at the same time.