I could mean you could mean he could mean we could mean you could mean they could mean
V-ing form
I could be meaning you could be meaning he could be meaning we could be meaning you could be meaning they could be meaning
Perfect
I could have meant you could have meant he could have meant we could have meant you could have meant they could have meant
V-ing perfect
I could have been meaning you could have been meaning he could have been meaning we could have been meaning you could have been meaning they could have been meaning
Negation
Simple form
I could not mean you could not mean he could not mean we could not mean you could not mean they could not mean
V-ing form
I could not be meaning you could not be meaning he could not be meaning we could not be meaning you could not be meaning they could not be meaning
Perfect
I could not have meant you could not have meant he could not have meant we could not have meant you could not have meant they could not have meant
V-ing perfect
I could not have been meaning you could not have been meaning he could not have been meaning we could not have been meaning you could not have been meaning they could not have been meaning
Interrogative form
Simple form
could I mean? could you mean? could he mean? could we mean? could you mean? could they mean?
V-ing form
could I be meaning? could you be meaning? could he be meaning? could we be meaning? could you be meaning? could they be meaning?
Perfect
could I have meant? could you have meant? could he have meant? could we have meant? could you have meant? could they have meant?
V-ing perfect
could I have been meaning? could you have been meaning? could he have been meaning? could we have been meaning? could you have been meaning? could they have been meaning?
Interro-negative form
Simple form
could I not mean? could you not mean? could he not mean? could we not mean? could you not mean? could they not mean?
V-ing form
could I not be meaning? could you not be meaning? could he not be meaning? could we not be meaning? could you not be meaning? could they not be meaning?
Perfect
could I not have meant? could you not have meant? could he not have meant? could we not have meant? could you not have meant? could they not have meant?
V-ing perfect
could I not have been meaning? could you not have been meaning? could he not have been meaning? could we not have been meaning? could you not have been meaning? could they not have been meaning?