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