<p>If my grammar mistakes are so subtle that my English teacher cannot find them, and since you won't point them out, I'm not wasting my time checking every English teacher in the school to find one. My English teacher knows her stuff, she's won writing awards and has taught for years, so there can't be anything too glaring. She may have missed something, yes, but it can't be anything too huge. It doesn't help me just to tell me that there are "quite a few" mistakes if you won't point them out.</p>