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