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