I could approve you could approve he could approve we could approve you could approve they could approve
V-ing form
I could be approving you could be approving he could be approving we could be approving you could be approving they could be approving
Perfect
I could have approved you could have approved he could have approved we could have approved you could have approved they could have approved
V-ing perfect
I could have been approving you could have been approving he could have been approving we could have been approving you could have been approving they could have been approving
Negation
Simple form
I couldn't approve you couldn't approve he couldn't approve we couldn't approve you couldn't approve they couldn't approve
V-ing form
I couldn't be approving you couldn't be approving he couldn't be approving we couldn't be approving you couldn't be approving they couldn't be approving
Perfect
I couldn't have approved you couldn't have approved he couldn't have approved we couldn't have approved you couldn't have approved they couldn't have approved
V-ing perfect
I couldn't have been approving you couldn't have been approving he couldn't have been approving we couldn't have been approving you couldn't have been approving they couldn't have been approving
Interrogative form
Simple form
could I approve? could you approve? could he approve? could we approve? could you approve? could they approve?
V-ing form
could I be approving? could you be approving? could he be approving? could we be approving? could you be approving? could they be approving?
Perfect
could I have approved? could you have approved? could he have approved? could we have approved? could you have approved? could they have approved?
V-ing perfect
could I have been approving? could you have been approving? could he have been approving? could we have been approving? could you have been approving? could they have been approving?
Interro-negative form
Simple form
couldn't I approve? couldn't you approve? couldn't he approve? couldn't we approve? couldn't you approve? couldn't they approve?
V-ing form
couldn't I be approving? couldn't you be approving? couldn't he be approving? couldn't we be approving? couldn't you be approving? couldn't they be approving?
Perfect
couldn't I have approved? couldn't you have approved? couldn't he have approved? couldn't we have approved? couldn't you have approved? couldn't they have approved?
V-ing perfect
couldn't I have been approving? couldn't you have been approving? couldn't he have been approving? couldn't we have been approving? couldn't you have been approving? couldn't they have been approving?