I could pulse you could pulse he could pulse we could pulse you could pulse they could pulse
V-ing form
I could be pulsing you could be pulsing he could be pulsing we could be pulsing you could be pulsing they could be pulsing
Perfect
I could have pulsed you could have pulsed he could have pulsed we could have pulsed you could have pulsed they could have pulsed
V-ing perfect
I could have been pulsing you could have been pulsing he could have been pulsing we could have been pulsing you could have been pulsing they could have been pulsing
Negation
Simple form
I couldn't pulse you couldn't pulse he couldn't pulse we couldn't pulse you couldn't pulse they couldn't pulse
V-ing form
I couldn't be pulsing you couldn't be pulsing he couldn't be pulsing we couldn't be pulsing you couldn't be pulsing they couldn't be pulsing
Perfect
I couldn't have pulsed you couldn't have pulsed he couldn't have pulsed we couldn't have pulsed you couldn't have pulsed they couldn't have pulsed
V-ing perfect
I couldn't have been pulsing you couldn't have been pulsing he couldn't have been pulsing we couldn't have been pulsing you couldn't have been pulsing they couldn't have been pulsing
Interrogative form
Simple form
could I pulse? could you pulse? could he pulse? could we pulse? could you pulse? could they pulse?
V-ing form
could I be pulsing? could you be pulsing? could he be pulsing? could we be pulsing? could you be pulsing? could they be pulsing?
Perfect
could I have pulsed? could you have pulsed? could he have pulsed? could we have pulsed? could you have pulsed? could they have pulsed?
V-ing perfect
could I have been pulsing? could you have been pulsing? could he have been pulsing? could we have been pulsing? could you have been pulsing? could they have been pulsing?
Interro-negative form
Simple form
couldn't I pulse? couldn't you pulse? couldn't he pulse? couldn't we pulse? couldn't you pulse? couldn't they pulse?
V-ing form
couldn't I be pulsing? couldn't you be pulsing? couldn't he be pulsing? couldn't we be pulsing? couldn't you be pulsing? couldn't they be pulsing?
Perfect
couldn't I have pulsed? couldn't you have pulsed? couldn't he have pulsed? couldn't we have pulsed? couldn't you have pulsed? couldn't they have pulsed?
V-ing perfect
couldn't I have been pulsing? couldn't you have been pulsing? couldn't he have been pulsing? couldn't we have been pulsing? couldn't you have been pulsing? couldn't they have been pulsing?