I could blat you could blat he could blat we could blat you could blat they could blat
V-ing form
I could be blating you could be blating he could be blating we could be blating you could be blating they could be blating
Perfect
I could have blated you could have blated he could have blated we could have blated you could have blated they could have blated
V-ing perfect
I could have been blating you could have been blating he could have been blating we could have been blating you could have been blating they could have been blating
Negation
Simple form
I could not blat you could not blat he could not blat we could not blat you could not blat they could not blat
V-ing form
I could not be blating you could not be blating he could not be blating we could not be blating you could not be blating they could not be blating
Perfect
I could not have blated you could not have blated he could not have blated we could not have blated you could not have blated they could not have blated
V-ing perfect
I could not have been blating you could not have been blating he could not have been blating we could not have been blating you could not have been blating they could not have been blating
Interrogative form
Simple form
could I blat? could you blat? could he blat? could we blat? could you blat? could they blat?
V-ing form
could I be blating? could you be blating? could he be blating? could we be blating? could you be blating? could they be blating?
Perfect
could I have blated? could you have blated? could he have blated? could we have blated? could you have blated? could they have blated?
V-ing perfect
could I have been blating? could you have been blating? could he have been blating? could we have been blating? could you have been blating? could they have been blating?
Interro-negative form
Simple form
could I not blat? could you not blat? could he not blat? could we not blat? could you not blat? could they not blat?
V-ing form
could I not be blating? could you not be blating? could he not be blating? could we not be blating? could you not be blating? could they not be blating?
Perfect
could I not have blated? could you not have blated? could he not have blated? could we not have blated? could you not have blated? could they not have blated?
V-ing perfect
could I not have been blating? could you not have been blating? could he not have been blating? could we not have been blating? could you not have been blating? could they not have been blating?