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