1 How was I supposed to know you'd break it./How was I to know you'd break it. BOTH <Yes, but this is a queston, so add ? at the end.>
2 If I had to walk any further/farther with this in hand<,> I wouldn't have been able to as I was losing grip of the furniture./I had no grip. I don't know <farther -- used for distance. Either "losing my grip on the furniture" or "I had no grip on the furniture" -- "on" not "of">
3 Instead of laughing/rather than laughing at stuff I do, come and help me. BOTH <Yes>

4 How many turns to unscrew the screw/before unscrewing the screw. I don't know TO unscrew I think <Okay, but you could say "before the screw is unscrewed."  Also, this is a question, so add the ? at the end.>
5 My arms are tiring/are getting tired. BOTH <Yes>
6 Get off the subway to let the others off and wait for them to get off before/to get back on. BEFORE GETTING BACK ON <Yes.  But you can also say "before you get back on.">
7 Her way of dressing is the one I like most/the most BOTH <You can use either but "the most" is preferable in formal usage.  You can also say "...is the one I prefer.">

8 All these/this stuff isn't mine./All these things aren't mine./All this /these furniture isn't mine. ALL THIS STUFF ISN'T MINE / ALL THESE THINGS AREN'T MINE./ ALL THIS FURNITURE ISN'T MINE. <Okay, but do you mean to say "This stuff isn't all mine"--meaning that some of it is?  Or do you mean to say "None of this stuff is mine"?>
9 What does/where does you 7th floor apartment overlook. BOTH <What does.>
10 Put a book under the legs of the table to make it higher/taller. (how would you say this?) DON'T KNOW <Either>

11 This lamp uses up a lot of energy/electrictiy plus I have no room to store. DON'T KNOW<Either, but change the ending to "I have no room to store it" or "I have no place to store it.">

12 My front door is on the landing/give on the landing. ON the landing I THINK <Yes>
13 How long does the timer stay on this number (for)? FOR is optional <I would either omit the "for" or start the sentence with it: "For how long ...">

14 Shake (is the word shake) your hands and wipe your hands on your shirt. I don't have a towel. DONT KNOW <Okay, but use a pronoun: Shake your hands and wipe them on your shirt.>
15 Its more annoying to desemble furniture than to assemble it as you have nothing to look forward to. I DONT KNOW IF DISSEMBLE IS AN ANTONYM FOR ASSEMBLE?? <The word you want is "disassemble." Dissemble means to lie by concealing facts or the truth of a situation.  Also, use "it's" not "its" at the start of your sentence--the first word means "it is" and the second word means "belonging to it.">

16 Anything to cover up the walls is good, painting etc.. OK <Yes>

17 This will decrease/reduce the crime rate. BOTH <Yes>

18 Run the jar under/on hot water if you can't open it and try not spilling any of the water in the jar opening it/while opening it. DONT KNOW <Like this: Run the jar under hot water if you can't open it and try not to spill any of the water into the jar while opening it.>

19 I have 10 dollars left till/to the beginning of next month. TILL <Yes>

20 I'll ask my dad for as much money as I can/possible. BOTH <Yes>

21 I need small sized /size jean. I DONT KNOW <Informally, either, but small-sized jeans would be preferable.  Or you could say "I need jeans in a small size.">

22 These clip on laptop lamps that you buy give off enough light so 2 computers can use it./lightens two computers. I don't know <The first is more correct, although I think the light would be used by "computer users" not "computers."  You don't want the word "lighten," which means to reduce the darkness of.  You lighten the color of your hair, for example.  I think you want to say "...give off enough light to light two computers." >