Everything your English teacher never told you

I feel like half my job as an editor is expunging grammar rules taught by English teachers who never bothered to read a usage manual written after 1820. Kids get to college knowing their teachers' grammar peeves by heart, but with little knowledge on how to write a thorough essay.

But that's a topic for another day . . .

In the freelance realm especially, people often come back to me with comments like, "But wait—I was taught that this was wrong."

Well, I'm here to tell you what your English teachers likely didn't:

• It's okay to end a sentence with a preposition.
• It's okay to split an infinitive.
• It's okay to start a sentence with a conjunction.
• You are probably capitalizing too much.
• Just use the singular they—those who are against it are losing the battle. 
• Ain't is too a word. (Although you probably shouldn't use it in anything remotely formal—the prejudice against this word is still very strong.)
• Language changes. It's not the end of the world.

The English language is nonsensical a lot of the time, which is why I refrain from grammar scolding. But lately, it's been the incorrectly taught rules that people stubbornly cling to that make me want to throw small objects and punch desks.