I could complain you could complain he could complain we could complain you could complain they could complain
V-ing form
I could be complaining you could be complaining he could be complaining we could be complaining you could be complaining they could be complaining
Perfect
I could have complained you could have complained he 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 he 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 he 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 he 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 he 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 he 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 he complain? could we complain? could you complain? could they complain?
V-ing form
could I be complaining? could you be complaining? could he be complaining? could we be complaining? could you be complaining? could they be complaining?
Perfect
could I have complained? could you have complained? could he 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 he 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 he 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 he 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 he 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 he not have been complaining? could we not have been complaining? could you not have been complaining? could they not have been complaining?