It's a statement of approval. It depends how serious the relationship is - but yes, it could mean marriage. Or even just a date!

"1. If it were to rain tomorrow, what will you do?" 'were' is past tense, and 'will' is future tense. It would be better if they matched, so, this would be better, "If it rains tomorrow, what will you do?" OR "If it were to rain tomorrow, what would you do?" 2 looks good! "3. This old man had 2 millions dollars, and he gave it to charities." This is good but for a number under ten, you should probably spell it out. So, "two million dollars." "4. He should eat lots of fruits and vegetables and drinks lots of water." The word "water" is plural, so drinks doesn't need the s. Just, "and drink lots of water." "5. He doesn’t know if should he bring a present when invited." There is a circumstance where this phrasing works: The boy knows he will be invited somewhere at a future date, but the invitation has not yet occurred. I doubt this is the situation you're talking about, though. It should probably be, "He didn't know if he should bring a present when invited." "6. If we had left earlier this morning, we wouldn’t miss the bus." Past and future tense mix up again. "If we had left earlier this morning, we wouldn't have missed the bus." 7 is a strange sentiment but grammatically fine, haha. "8. If I were you, I would talk to someone who look friendly" should be "looks friendly." 9 is perfect! "10. I can’t sleep with the night before taking a big exam." should be "I can't sleep on the night" or "can't sleep during the night." 11 is perfect, though it should end in a question mark. "12. Confident people dare to speak in the public." This does not need "the." 13 is perfect! "14. I really need it because of I have a math test" this needs a comma! And no 'of' "I really need it, because I have a math test." You could get rid of 'because,' too. 15 is great! "16. I am really anxious, because I can’t find out my backpack." 'Out' shouldn't be there. "Because I can't find my backpack." "17. Strange things are happened in our neighborhood." Tense mix up again! "Are happening" or "have happened" 18 is great! "19. Social situations aren’t bother you in the slightest." 'Aren't' should be 'don't' "20. Sometime you might annoy people because you’re so confident." Should be "sometimes you might." Also I noticed that you left off a lot of periods at the ends of your sentences, I assume you know about that already.

Central American accent, the most boring to ever exist. :(

It depends on the person, I think. I'm friends with one of my exes, but even being around the other one makes me want to curl up with embarrassment!

The usual phrase is something like, "People with weak hearts shouldn't watch this." the idea being that it could cause a heart attack or make you faint, etc. 'Disease' is bad for this because there are many heart diseases that don't lead to heart attacks or fainting.

It's just a positive exclamation like "Oh boy!" or "Hurray!"

The concept of 'friendship' totally varies from person to person. The west is influenced by a lot of different cultures and different people are raised with different ideas of what is appropriate, and when you should say 'no, sorry' to a friend. "if your friend and you have a fight,being angry to each other,will you say it out directly and solve the problem?or just 'hide' it in mind and let it fade away?" It depends on the severity of the anger/problem. If my friend just made a mistake or said one thing that hurt my feelings, I would probably just let it pass and ignore it. If they were doing or saying something repeatedly, many times, that hurt my feelings, I would probably confront them. I find confronting the problem usually solves it, yes.

I Googled to get the full quote: "A child’s wooden blocks. She picked up the nearest one, her breath catching. Tilted toward the window, the embossed letter caught enough light to show its cruel hook, its sharp teeth. J." From this context I think the author is quite literally describing the letter J. The bottom of it could be seen as a 'hook.' The sharp teeth is confusing me, though. I think this is a case of 'purple prose' running amok. The author is just trying to set the mood of his story by using (ridiculously) ominous words to describe the scene.