Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could gasser you could gasser he could gasser we could gasser you could gasser they could gasser
V-ing form
I could be gassering you could be gassering he could be gassering we could be gassering you could be gassering they could be gassering
Perfect
I could have gassered you could have gassered he could have gassered we could have gassered you could have gassered they could have gassered
V-ing perfect
I could have been gassering you could have been gassering he could have been gassering we could have been gassering you could have been gassering they could have been gassering
Negation
Simple form
I couldn't gasser you couldn't gasser he couldn't gasser we couldn't gasser you couldn't gasser they couldn't gasser
V-ing form
I couldn't be gassering you couldn't be gassering he couldn't be gassering we couldn't be gassering you couldn't be gassering they couldn't be gassering
Perfect
I couldn't have gassered you couldn't have gassered he couldn't have gassered we couldn't have gassered you couldn't have gassered they couldn't have gassered
V-ing perfect
I couldn't have been gassering you couldn't have been gassering he couldn't have been gassering we couldn't have been gassering you couldn't have been gassering they couldn't have been gassering
Interrogative form
Simple form
could I gasser? could you gasser? could he gasser? could we gasser? could you gasser? could they gasser?
V-ing form
could I be gassering? could you be gassering? could he be gassering? could we be gassering? could you be gassering? could they be gassering?
Perfect
could I have gassered? could you have gassered? could he have gassered? could we have gassered? could you have gassered? could they have gassered?
V-ing perfect
could I have been gassering? could you have been gassering? could he have been gassering? could we have been gassering? could you have been gassering? could they have been gassering?
Interro-negative form
Simple form
couldn't I gasser? couldn't you gasser? couldn't he gasser? couldn't we gasser? couldn't you gasser? couldn't they gasser?
V-ing form
couldn't I be gassering? couldn't you be gassering? couldn't he be gassering? couldn't we be gassering? couldn't you be gassering? couldn't they be gassering?
Perfect
couldn't I have gassered? couldn't you have gassered? couldn't he have gassered? couldn't we have gassered? couldn't you have gassered? couldn't they have gassered?
V-ing perfect
couldn't I have been gassering? couldn't you have been gassering? couldn't he have been gassering? couldn't we have been gassering? couldn't you have been gassering? couldn't they have been gassering?