Английский язык, intermediate.

A)
could
be able to
couldnt
not being able to
be able to

couldnt
be able to
couldnt
can
being able to
wouldnt be able to

b)
2) couldnt remember
3) be able to
4) can
5) been able to
6) couldnt
7) being able to
8) cant
9) being able to
10) be able to
11) be able to
12) cant