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 cannot push you cannot push she cannot push we cannot push you cannot push they cannot push
V-ing form
I cannot be pushing you cannot be pushing she cannot be pushing we cannot be pushing you cannot be pushing they cannot be pushing
Perfect
I cannot have pushed you cannot have pushed she cannot have pushed we cannot have pushed you cannot have pushed they cannot have pushed
V-ing perfect
I cannot have been pushing you cannot have been pushing she cannot have been pushing we cannot have been pushing you cannot have been pushing they cannot 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 I not push? can you not push? can she not push? can we not push? can you not push? can they not push?
V-ing form
can I not be pushing? can you not be pushing? can she not be pushing? can we not be pushing? can you not be pushing? can they not be pushing?
Perfect
can I not have pushed? can you not have pushed? can she not have pushed? can we not have pushed? can you not have pushed? can they not have pushed?
V-ing perfect
can I not have been pushing? can you not have been pushing? can she not have been pushing? can we not have been pushing? can you not have been pushing? can they not have been pushing?