1.Could write => could + V
2.Couldn't attend =>could + V
3.Couldn't get =>could + V
4.Couldn't arrive =>could + V
5.Could speak =>could + V
6.Couldn't understand =>could + V
7.Could play => could + V
8.Could open => could + V
9.Could play => could + V
10.Couldn't find => could + V