1)I have built the small house.
2)I have built the small house,when I came from school
3)I haven't never built the small house.
4)I haven't built the small house yet.
5)Have you ever built towers?
6)We built a house yesterday.
7)I haven't learned the words.
8)We didn't do homework.
9)They haven't never seen crocodile.
10)They didn't see crocodile yesterday.