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