I could stroll you could stroll he could stroll we could stroll you could stroll they could stroll
V-ing form
I could be strolling you could be strolling he could be strolling we could be strolling you could be strolling they could be strolling
Perfect
I could have strolled you could have strolled he could have strolled we could have strolled you could have strolled they could have strolled
V-ing perfect
I could have been strolling you could have been strolling he could have been strolling we could have been strolling you could have been strolling they could have been strolling
Negation
Simple form
I could not stroll you could not stroll he could not stroll we could not stroll you could not stroll they could not stroll
V-ing form
I could not be strolling you could not be strolling he could not be strolling we could not be strolling you could not be strolling they could not be strolling
Perfect
I could not have strolled you could not have strolled he could not have strolled we could not have strolled you could not have strolled they could not have strolled
V-ing perfect
I could not have been strolling you could not have been strolling he could not have been strolling we could not have been strolling you could not have been strolling they could not have been strolling
Interrogative form
Simple form
could I stroll? could you stroll? could he stroll? could we stroll? could you stroll? could they stroll?
V-ing form
could I be strolling? could you be strolling? could he be strolling? could we be strolling? could you be strolling? could they be strolling?
Perfect
could I have strolled? could you have strolled? could he have strolled? could we have strolled? could you have strolled? could they have strolled?
V-ing perfect
could I have been strolling? could you have been strolling? could he have been strolling? could we have been strolling? could you have been strolling? could they have been strolling?
Interro-negative form
Simple form
could I not stroll? could you not stroll? could he not stroll? could we not stroll? could you not stroll? could they not stroll?
V-ing form
could I not be strolling? could you not be strolling? could he not be strolling? could we not be strolling? could you not be strolling? could they not be strolling?
Perfect
could I not have strolled? could you not have strolled? could he not have strolled? could we not have strolled? could you not have strolled? could they not have strolled?
V-ing perfect
could I not have been strolling? could you not have been strolling? could he not have been strolling? could we not have been strolling? could you not have been strolling? could they not have been strolling?