I could chain-smoke you could chain-smoke she could chain-smoke we could chain-smoke you could chain-smoke they could chain-smoke
V-ing form
I could be chain-smoking you could be chain-smoking she could be chain-smoking we could be chain-smoking you could be chain-smoking they could be chain-smoking
Perfect
I could have chain-smoked you could have chain-smoked she could have chain-smoked we could have chain-smoked you could have chain-smoked they could have chain-smoked
V-ing perfect
I could have been chain-smoking you could have been chain-smoking she could have been chain-smoking we could have been chain-smoking you could have been chain-smoking they could have been chain-smoking
Negation
Simple form
I could not chain-smoke you could not chain-smoke she could not chain-smoke we could not chain-smoke you could not chain-smoke they could not chain-smoke
V-ing form
I could not be chain-smoking you could not be chain-smoking she could not be chain-smoking we could not be chain-smoking you could not be chain-smoking they could not be chain-smoking
Perfect
I could not have chain-smoked you could not have chain-smoked she could not have chain-smoked we could not have chain-smoked you could not have chain-smoked they could not have chain-smoked
V-ing perfect
I could not have been chain-smoking you could not have been chain-smoking she could not have been chain-smoking we could not have been chain-smoking you could not have been chain-smoking they could not have been chain-smoking
Interrogative form
Simple form
could I chain-smoke? could you chain-smoke? could she chain-smoke? could we chain-smoke? could you chain-smoke? could they chain-smoke?
V-ing form
could I be chain-smoking? could you be chain-smoking? could she be chain-smoking? could we be chain-smoking? could you be chain-smoking? could they be chain-smoking?
Perfect
could I have chain-smoked? could you have chain-smoked? could she have chain-smoked? could we have chain-smoked? could you have chain-smoked? could they have chain-smoked?
V-ing perfect
could I have been chain-smoking? could you have been chain-smoking? could she have been chain-smoking? could we have been chain-smoking? could you have been chain-smoking? could they have been chain-smoking?
Interro-negative form
Simple form
could I not chain-smoke? could you not chain-smoke? could she not chain-smoke? could we not chain-smoke? could you not chain-smoke? could they not chain-smoke?
V-ing form
could I not be chain-smoking? could you not be chain-smoking? could she not be chain-smoking? could we not be chain-smoking? could you not be chain-smoking? could they not be chain-smoking?
Perfect
could I not have chain-smoked? could you not have chain-smoked? could she not have chain-smoked? could we not have chain-smoked? could you not have chain-smoked? could they not have chain-smoked?
V-ing perfect
could I not have been chain-smoking? could you not have been chain-smoking? could she not have been chain-smoking? could we not have been chain-smoking? could you not have been chain-smoking? could they not have been chain-smoking?