I could market you could market he could market we could market you could market they could market
V-ing form
I could be marketing you could be marketing he could be marketing we could be marketing you could be marketing they could be marketing
Perfect
I could have marketed you could have marketed he could have marketed we could have marketed you could have marketed they could have marketed
V-ing perfect
I could have been marketing you could have been marketing he could have been marketing we could have been marketing you could have been marketing they could have been marketing
Negation
Simple form
I could not market you could not market he could not market we could not market you could not market they could not market
V-ing form
I could not be marketing you could not be marketing he could not be marketing we could not be marketing you could not be marketing they could not be marketing
Perfect
I could not have marketed you could not have marketed he could not have marketed we could not have marketed you could not have marketed they could not have marketed
V-ing perfect
I could not have been marketing you could not have been marketing he could not have been marketing we could not have been marketing you could not have been marketing they could not have been marketing
Interrogative form
Simple form
could I market? could you market? could he market? could we market? could you market? could they market?
V-ing form
could I be marketing? could you be marketing? could he be marketing? could we be marketing? could you be marketing? could they be marketing?
Perfect
could I have marketed? could you have marketed? could he have marketed? could we have marketed? could you have marketed? could they have marketed?
V-ing perfect
could I have been marketing? could you have been marketing? could he have been marketing? could we have been marketing? could you have been marketing? could they have been marketing?
Interro-negative form
Simple form
could I not market? could you not market? could he not market? could we not market? could you not market? could they not market?
V-ing form
could I not be marketing? could you not be marketing? could he not be marketing? could we not be marketing? could you not be marketing? could they not be marketing?
Perfect
could I not have marketed? could you not have marketed? could he not have marketed? could we not have marketed? could you not have marketed? could they not have marketed?
V-ing perfect
could I not have been marketing? could you not have been marketing? could he not have been marketing? could we not have been marketing? could you not have been marketing? could they not have been marketing?