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