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