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