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