I could size you could size he could size we could size you could size they could size
V-ing form
I could be sizing you could be sizing he could be sizing we could be sizing you could be sizing they could be sizing
Perfect
I could have sized you could have sized he could have sized we could have sized you could have sized they could have sized
V-ing perfect
I could have been sizing you could have been sizing he could have been sizing we could have been sizing you could have been sizing they could have been sizing
Negation
Simple form
I could not size you could not size he could not size we could not size you could not size they could not size
V-ing form
I could not be sizing you could not be sizing he could not be sizing we could not be sizing you could not be sizing they could not be sizing
Perfect
I could not have sized you could not have sized he could not have sized we could not have sized you could not have sized they could not have sized
V-ing perfect
I could not have been sizing you could not have been sizing he could not have been sizing we could not have been sizing you could not have been sizing they could not have been sizing
Interrogative form
Simple form
could I size? could you size? could he size? could we size? could you size? could they size?
V-ing form
could I be sizing? could you be sizing? could he be sizing? could we be sizing? could you be sizing? could they be sizing?
Perfect
could I have sized? could you have sized? could he have sized? could we have sized? could you have sized? could they have sized?
V-ing perfect
could I have been sizing? could you have been sizing? could he have been sizing? could we have been sizing? could you have been sizing? could they have been sizing?
Interro-negative form
Simple form
could I not size? could you not size? could he not size? could we not size? could you not size? could they not size?
V-ing form
could I not be sizing? could you not be sizing? could he not be sizing? could we not be sizing? could you not be sizing? could they not be sizing?
Perfect
could I not have sized? could you not have sized? could he not have sized? could we not have sized? could you not have sized? could they not have sized?
V-ing perfect
could I not have been sizing? could you not have been sizing? could he not have been sizing? could we not have been sizing? could you not have been sizing? could they not have been sizing?