As long as its clear by context what "my own" refers to, because this is an abbreviated way of saying something like: "I can pay for my own meal" or "I can pay for my own ticket."

"Go to school" is used when you are a student, and you will be attending class. The phrase is used by students. "Go to the school" is used when you are going to the building for something other than learning. Usually you are not a student if you are saying it this way. For example: "I am going to the school and talking to that teacher about my son." "Go to school and get your books."

Long distance friendship isn't hard with modern technology, although it's always nice to see each other in person once in a while. I've known my best friend for 20 years, but we've lived at least 300 miles apart for at least 15 of them. Long distance romantic relationships are much, much more difficult. In my experience, they rarely succeed.

I find this question amusing, because I just mentioned this morning that even as an educated native English speaker, I don't always know for sure whether I need to include the word "that" or not. In practice, it doesn't matter. I am understood either way and I think 99%+ of the American population wouldn't notice. I think a "that" here would be most correct, but it is understood fine either way.

I agree with Peachey, but want to add one thing. You can use "there you go" to congratulate someone. For example, I am teaching you English and you finally get your pronunciation correct. I could say, "There you go!" to show you that you did it correctly. It's another way of saying, "You did it correctly!"

Well, the difference is not so obvious that a native speaker (like me) can think of a simple explanation. "Amid" is very formal and old-fashioned. You won't hear it in daily speech. I'd expect to hear it at the start of a fairy tale or a documentary. "Amid" can be used to describe the middle of an action or event. This is the only time where you can't substitute "among" for "amid." But it's still very formal. I'd say "in the middle of" instead.

Honestly, none of them sound 100% correct to my ear. I think these two are technically correct, but they don't sound "American" to me: Don’t read such books that you don’t understand. He is such a clever boy that we all like him. I think the word "such" is uncommonly used in American English. I think the only time I use it to say: "Don't be such an idiot" or "Don't be such a jerk" Adding anything more to sentence sounds weird and makes me want to think of a simpler way to say it.

Very close. Should be: "Why is your stuff still here?"