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