I could veto you could veto she could veto we could veto you could veto they could veto
V-ing form
I could be vetoing you could be vetoing she could be vetoing we could be vetoing you could be vetoing they could be vetoing
Perfect
I could have vetoed you could have vetoed she could have vetoed we could have vetoed you could have vetoed they could have vetoed
V-ing perfect
I could have been vetoing you could have been vetoing she could have been vetoing we could have been vetoing you could have been vetoing they could have been vetoing
Negation
Simple form
I couldn't veto you couldn't veto she couldn't veto we couldn't veto you couldn't veto they couldn't veto
V-ing form
I couldn't be vetoing you couldn't be vetoing she couldn't be vetoing we couldn't be vetoing you couldn't be vetoing they couldn't be vetoing
Perfect
I couldn't have vetoed you couldn't have vetoed she couldn't have vetoed we couldn't have vetoed you couldn't have vetoed they couldn't have vetoed
V-ing perfect
I couldn't have been vetoing you couldn't have been vetoing she couldn't have been vetoing we couldn't have been vetoing you couldn't have been vetoing they couldn't have been vetoing
Interrogative form
Simple form
could I veto? could you veto? could she veto? could we veto? could you veto? could they veto?
V-ing form
could I be vetoing? could you be vetoing? could she be vetoing? could we be vetoing? could you be vetoing? could they be vetoing?
Perfect
could I have vetoed? could you have vetoed? could she have vetoed? could we have vetoed? could you have vetoed? could they have vetoed?
V-ing perfect
could I have been vetoing? could you have been vetoing? could she have been vetoing? could we have been vetoing? could you have been vetoing? could they have been vetoing?
Interro-negative form
Simple form
couldn't I veto? couldn't you veto? couldn't she veto? couldn't we veto? couldn't you veto? couldn't they veto?
V-ing form
couldn't I be vetoing? couldn't you be vetoing? couldn't she be vetoing? couldn't we be vetoing? couldn't you be vetoing? couldn't they be vetoing?
Perfect
couldn't I have vetoed? couldn't you have vetoed? couldn't she have vetoed? couldn't we have vetoed? couldn't you have vetoed? couldn't they have vetoed?
V-ing perfect
couldn't I have been vetoing? couldn't you have been vetoing? couldn't she have been vetoing? couldn't we have been vetoing? couldn't you have been vetoing? couldn't they have been vetoing?