in a post, one that i didn't want to hijack because of the subject matter, you responded: "Couldn't of said it better myself."
it's a good response. however, it would be "couldn't've said", because what you are doing is making a contraction of three words: could not have. it's perfectly legal in english to make it like that, but you have to use the proper phrase. if you plan on going to college or technical school, then you'll likely take the SATs. that is a question on the test.
in one part, they ask you to identify problems or errors with sentences and, of the possible responses, one of them is "nothing wrong with this sentence (paraphrased)". they present a sentence comparable to the way you provided your response to the thread, and then provide four answers and the last one is "nothing wrong". hopefully, now you will get that question correct on the SATs, should you take them. if not, perhaps i won't see you making that mistake again?
i am in no way flaming you or attacking you personally. this is an attempt to improve your written language skills. if it was in any other thread, i probably would've hijacked it, but the dude is feeling bad enough as it is without having someone appear to not be paying attention to his thread and hijacking it with something else instead.
p.s. i make mistakes when typing sometimes, too. i am far from perfect.