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