Sometimes that's will fit better than it's and vice versa. It all depends on the context of your sentence. (: Hope this helped!

1.) The sentence is correct, but the sentence order sounds a bit unnatural in my opinion. (: You will be more likely to hear "he didn't come back until midnight" in an everyday conversation. "Not until midnight did he come back" sounds more narrative, and is most likely to be found in writing rather than spoken. 2.) For this one, I can only speak for American schools. This is what I most commonly hear the head of the schools called: Elementary School (Grade School): Prinicipal Middle School (Junior High): Principal High School: Principal College (University): Dean

The first sentence is correct! As for the second sentence, it would be more gramatically correct to say "I haven't given up on my dream." Both sentences can be used depending on what tense you are speaking in. "I didn't give up on my dream" refers to the past. For example, you could say, "It was hard, but I didn't give up on my dream." Again, you would be saying that, in the past, you did not give up on your dream. This also might give the impression that your dream came true. "I haven't given up on my dream" refers to the present. When you say this, you are implying that you still believe in your dream, and you (most likely) don't plan on giving up on it. Hope this helped! (:

1.) It is easy to understand what you are trying to say, but it sounds a bit unnatural. I would say, "Keep this to yourself and don't tell anyone." "Keep this news to yourself." "Don't tell anyone." 2.) "Put off", "postpone", and "delay" all have very similar meanings. "Put off" is mostly used in casual settings and suggests procrastination. This means, for example, instead of doing your work, you could "put it off" by saying you will do it later. "Postpone" is usually used when talking about future events that have been officially "put off". Take for instance, your friend says "The football game has been postponed." This means that the game will still happen, but instead of the game occurring on its original date, it will happen another day. If the game occurs just a few hours later, then "delay" becomes a better word to use. "Delay" is usually used when something is moving slower or going to happen later than planned. Imagine you're at an airport and you hear "Due to weather conditions, flight 247 will experience a slight delay." This means that the flight will still take off, it will just be at 12:00 instead of 11:00. Sometimes these words can be used interchangeably, but in certain cases some words sound better than others. In my opinion, I would use them as: put off = procrastinate, to not get work done postpone = happens later than planned, on another day, week, etc. delay = happens later than planned, but on the same day 3.) My advice would be to choose your path based on your passions and what you love! Hope this helped! (: (: