I can lean you can lean he can lean we can lean you can lean they can lean
V-ing form
I can be leaning you can be leaning he can be leaning we can be leaning you can be leaning they can be leaning
Perfect
I can have leaned you can have leaned he can have leaned we can have leaned you can have leaned they can have leaned
V-ing perfect
I can have been leaning you can have been leaning he can have been leaning we can have been leaning you can have been leaning they can have been leaning
Negation
Simple form
I cannot lean you cannot lean he cannot lean we cannot lean you cannot lean they cannot lean
V-ing form
I cannot be leaning you cannot be leaning he cannot be leaning we cannot be leaning you cannot be leaning they cannot be leaning
Perfect
I cannot have leaned you cannot have leaned he cannot have leaned we cannot have leaned you cannot have leaned they cannot have leaned
V-ing perfect
I cannot have been leaning you cannot have been leaning he cannot have been leaning we cannot have been leaning you cannot have been leaning they cannot have been leaning
Interrogative form
Simple form
can I lean? can you lean? can he lean? can we lean? can you lean? can they lean?
V-ing form
can I be leaning? can you be leaning? can he be leaning? can we be leaning? can you be leaning? can they be leaning?
Perfect
can I have leaned? can you have leaned? can he have leaned? can we have leaned? can you have leaned? can they have leaned?
V-ing perfect
can I have been leaning? can you have been leaning? can he have been leaning? can we have been leaning? can you have been leaning? can they have been leaning?
Interro-negative form
Simple form
can I not lean? can you not lean? can he not lean? can we not lean? can you not lean? can they not lean?
V-ing form
can I not be leaning? can you not be leaning? can he not be leaning? can we not be leaning? can you not be leaning? can they not be leaning?
Perfect
can I not have leaned? can you not have leaned? can he not have leaned? can we not have leaned? can you not have leaned? can they not have leaned?
V-ing perfect
can I not have been leaning? can you not have been leaning? can he not have been leaning? can we not have been leaning? can you not have been leaning? can they not have been leaning?