There is more than one way to do it for most numbers, but here is one for each:
11 = 4/.4 + 4/4
12 = 4 x (4 - 4/4)
13 = 4! - 44/4
14 = (4 x 4) - (4 / sqrt(4))
15 = (4 x 4) - 4/4
16 = (4 x 4 x 4) / 4
17 = (4 x 4) + 4/4
18 = (4 x 4) + (4 / sqrt(4))
19 = 4! - 4 - 4/4
20 = 4 * (4 + 4/4)
You can't.
28,29,30,31.
Eight and four.
Yes: four cubic numbers are possible.
5x5x5x3=375
9
2 and 17
1,000 + 1,000 + 70 + 7 = 2077
hyp~95# 34 £
3,5,7,8
8 and 12
2593 + 17 + 13 + 2