I can't dare to guess how he trembled when he got the first letter. I fail to remember the exact moment when I got the first letter, but there was the impressive letter in my lifr. It was written by the x-boyfriend. He wrote the phase "I love u" at least 1000 times. Unfortunately he fell in love with my best friend. -> lifr (typo) to "life". x-boyfriend to "ex-boyfriend" (ex means former...ex-military, ex-girlfriend, ex-husband, ex-wife) "but there was the impressive letter in my life" I don't quite understand your meaning here. Perhaps "but it was the most impressive letter in my life" or "but it was the most memorable letter in my life" "the ex-boyfriend" -> "my ex-boyfriend" (sometimes you will hear people say "the ex-boyfriend/girlfriend/wife/husband" but that is casual/informal and often with someone who is familiar with that person. People will use it with a not ex-partner as well. "The wife is calling, I gotta answer this." "Ugh, the ex is at it again." It's usually to a friend and it really means "my") Phase (typo) -> "phrase" Harry got the worn-out uniform which had belonged to Dudely. He must have felt good as he wouldn't be with his cousin at school. He got the first letter for his entire life. Uncle Vernon deprived him of  the precious letter just before Harry opened it. The second two sentences are a bit confusing. I'll assume Dudely is Harry's cousin, so perhaps you meant... "He must have felt comforted by it, knowing he wouldn't be with his cousin at school. He got the first letter in his entire life." (first and last sentences are fine)

1. You're not allowed to go out after 7pm. PERFECT You can also just say "You're not allowed out after 7pm." Both are fine and mean the same thing. You can omit "to go" as it's implied/understood when you're speaking casually.  2. Those things are not allowed to carry on the plane. -> Those things are not allowed on the plane. Those things are not permitted on the plane. Those things can't be brought on the plane. Those things are not allowed/permitted (to be brought/stored) in carry-on on the plane. (carry-on is a specific type of luggage and section of storage in the passenger section of a plane)            3. Harry was not allowed to have a question of how his parents passed away. -> Harry was not allowed to question how his parents passed away. ("to question" is a verb itself. "allowed to have a question of how" sounds very strange/unnatural) 'Harry was on the point of unfolding his letter, which was written on the same heavy parchment as the envelope, when it was jerked sharply out of his hand by Uncle Vernon' -> Harry was on the verge of unfolding his letter, (the rest is correct and natural) OR Harry was finally at the point of unfolding his letter, on the verge of = just about to do something, sounds intense/suspenseful, often followed by an interruption (ex. He was on the verge of discovering the killer, when suddenly he got a call that his family had been kidnapped and was being held hostage. / She was on the verge of tears. / They were on the verge of an incredible scientific breakthrough!) finally to the point / finally at the point / finally reach that point (exact variation depends on the sentence) -> everything has led up to this moment and at last it's happening "We're finally to / at the point in our presentation where we can have some fun and do a group activity together." (you could also say "part" in this case) "I've finally reach the point in the book where Sarah gets murdered!" (you could also say "part" in this case)