I could shudder you could shudder she could shudder we could shudder you could shudder they could shudder
V-ing form
I could be shuddering you could be shuddering she could be shuddering we could be shuddering you could be shuddering they could be shuddering
Perfect
I could have shuddered you could have shuddered she could have shuddered we could have shuddered you could have shuddered they could have shuddered
V-ing perfect
I could have been shuddering you could have been shuddering she could have been shuddering we could have been shuddering you could have been shuddering they could have been shuddering
Negation
Simple form
I could not shudder you could not shudder she could not shudder we could not shudder you could not shudder they could not shudder
V-ing form
I could not be shuddering you could not be shuddering she could not be shuddering we could not be shuddering you could not be shuddering they could not be shuddering
Perfect
I could not have shuddered you could not have shuddered she could not have shuddered we could not have shuddered you could not have shuddered they could not have shuddered
V-ing perfect
I could not have been shuddering you could not have been shuddering she could not have been shuddering we could not have been shuddering you could not have been shuddering they could not have been shuddering
Interrogative form
Simple form
could I shudder? could you shudder? could she shudder? could we shudder? could you shudder? could they shudder?
V-ing form
could I be shuddering? could you be shuddering? could she be shuddering? could we be shuddering? could you be shuddering? could they be shuddering?
Perfect
could I have shuddered? could you have shuddered? could she have shuddered? could we have shuddered? could you have shuddered? could they have shuddered?
V-ing perfect
could I have been shuddering? could you have been shuddering? could she have been shuddering? could we have been shuddering? could you have been shuddering? could they have been shuddering?
Interro-negative form
Simple form
could I not shudder? could you not shudder? could she not shudder? could we not shudder? could you not shudder? could they not shudder?
V-ing form
could I not be shuddering? could you not be shuddering? could she not be shuddering? could we not be shuddering? could you not be shuddering? could they not be shuddering?
Perfect
could I not have shuddered? could you not have shuddered? could she not have shuddered? could we not have shuddered? could you not have shuddered? could they not have shuddered?
V-ing perfect
could I not have been shuddering? could you not have been shuddering? could she not have been shuddering? could we not have been shuddering? could you not have been shuddering? could they not have been shuddering?