I could throw you could throw he could throw we could throw you could throw they could throw
V-ing form
I could be throwing you could be throwing he could be throwing we could be throwing you could be throwing they could be throwing
Perfect
I could have thrown you could have thrown he could have thrown we could have thrown you could have thrown they could have thrown
V-ing perfect
I could have been throwing you could have been throwing he could have been throwing we could have been throwing you could have been throwing they could have been throwing
Negation
Simple form
I could not throw you could not throw he could not throw we could not throw you could not throw they could not throw
V-ing form
I could not be throwing you could not be throwing he could not be throwing we could not be throwing you could not be throwing they could not be throwing
Perfect
I could not have thrown you could not have thrown he could not have thrown we could not have thrown you could not have thrown they could not have thrown
V-ing perfect
I could not have been throwing you could not have been throwing he could not have been throwing we could not have been throwing you could not have been throwing they could not have been throwing
Interrogative form
Simple form
could I throw? could you throw? could he throw? could we throw? could you throw? could they throw?
V-ing form
could I be throwing? could you be throwing? could he be throwing? could we be throwing? could you be throwing? could they be throwing?
Perfect
could I have thrown? could you have thrown? could he have thrown? could we have thrown? could you have thrown? could they have thrown?
V-ing perfect
could I have been throwing? could you have been throwing? could he have been throwing? could we have been throwing? could you have been throwing? could they have been throwing?
Interro-negative form
Simple form
could I not throw? could you not throw? could he not throw? could we not throw? could you not throw? could they not throw?
V-ing form
could I not be throwing? could you not be throwing? could he not be throwing? could we not be throwing? could you not be throwing? could they not be throwing?
Perfect
could I not have thrown? could you not have thrown? could he not have thrown? could we not have thrown? could you not have thrown? could they not have thrown?
V-ing perfect
could I not have been throwing? could you not have been throwing? could he not have been throwing? could we not have been throwing? could you not have been throwing? could they not have been throwing?