I could complain you could complain she could complain we could complain you could complain they could complain
V-ing form
I could be complaining you could be complaining she could be complaining we could be complaining you could be complaining they could be complaining
Perfect
I could have complained you could have complained she could have complained we could have complained you could have complained they could have complained
V-ing perfect
I could have been complaining you could have been complaining she could have been complaining we could have been complaining you could have been complaining they could have been complaining
Negation
Simple form
I could not complain you could not complain she could not complain we could not complain you could not complain they could not complain
V-ing form
I could not be complaining you could not be complaining she could not be complaining we could not be complaining you could not be complaining they could not be complaining
Perfect
I could not have complained you could not have complained she could not have complained we could not have complained you could not have complained they could not have complained
V-ing perfect
I could not have been complaining you could not have been complaining she could not have been complaining we could not have been complaining you could not have been complaining they could not have been complaining
Interrogative form
Simple form
could I complain? could you complain? could she complain? could we complain? could you complain? could they complain?
V-ing form
could I be complaining? could you be complaining? could she be complaining? could we be complaining? could you be complaining? could they be complaining?
Perfect
could I have complained? could you have complained? could she have complained? could we have complained? could you have complained? could they have complained?
V-ing perfect
could I have been complaining? could you have been complaining? could she have been complaining? could we have been complaining? could you have been complaining? could they have been complaining?
Interro-negative form
Simple form
could I not complain? could you not complain? could she not complain? could we not complain? could you not complain? could they not complain?
V-ing form
could I not be complaining? could you not be complaining? could she not be complaining? could we not be complaining? could you not be complaining? could they not be complaining?
Perfect
could I not have complained? could you not have complained? could she not have complained? could we not have complained? could you not have complained? could they not have complained?
V-ing perfect
could I not have been complaining? could you not have been complaining? could she not have been complaining? could we not have been complaining? could you not have been complaining? could they not have been complaining?