Two authors who write articles and books on grammar came up with a list of the top mistakes that drive grammar nuts CRAZY. Here are a few of the most common mistakes grammar nerds hate to see . . .
1. Misplaced apostrophes. Like writing the word "it's" with an apostrophe, but you don't mean "it is."
2. Putting periods outside quotation marks. Unless you're in the U.K., they go inside.
3. Too many commas. A lot of people use them with no rhyme or reason now.
4. Using semicolons like commas. In general, they're mostly for linking two COMPLETE sentences that are closely related.
5. Two spaces after a period. That one's debatable. It used to be how everyone did it. But now people think the extra space is unnecessary and makes you seem old.
6. Capitalizing random words. Some people do it for emphasis now And it drives grammar nuts crazy. In general, the only words you capitalize are proper nouns, the first word in a sentence, and most words in a title.
7. Too many exclamation points. If a single email has more than two, you're overdoing it. And even for emphasis, you don't need more than two or three in a row.
(WRC-TV)