I can crouch you can crouch she can crouch we can crouch you can crouch they can crouch
V-ing form
I can be crouching you can be crouching she can be crouching we can be crouching you can be crouching they can be crouching
Perfect
I can have crouched you can have crouched she can have crouched we can have crouched you can have crouched they can have crouched
V-ing perfect
I can have been crouching you can have been crouching she can have been crouching we can have been crouching you can have been crouching they can have been crouching
Negation
Simple form
I can't crouch you can't crouch she can't crouch we can't crouch you can't crouch they can't crouch
V-ing form
I can't be crouching you can't be crouching she can't be crouching we can't be crouching you can't be crouching they can't be crouching
Perfect
I can't have crouched you can't have crouched she can't have crouched we can't have crouched you can't have crouched they can't have crouched
V-ing perfect
I can't have been crouching you can't have been crouching she can't have been crouching we can't have been crouching you can't have been crouching they can't have been crouching
Interrogative form
Simple form
can I crouch? can you crouch? can she crouch? can we crouch? can you crouch? can they crouch?
V-ing form
can I be crouching? can you be crouching? can she be crouching? can we be crouching? can you be crouching? can they be crouching?
Perfect
can I have crouched? can you have crouched? can she have crouched? can we have crouched? can you have crouched? can they have crouched?
V-ing perfect
can I have been crouching? can you have been crouching? can she have been crouching? can we have been crouching? can you have been crouching? can they have been crouching?
Interro-negative form
Simple form
can't I crouch? can't you crouch? can't she crouch? can't we crouch? can't you crouch? can't they crouch?
V-ing form
can't I be crouching? can't you be crouching? can't she be crouching? can't we be crouching? can't you be crouching? can't they be crouching?
Perfect
can't I have crouched? can't you have crouched? can't she have crouched? can't we have crouched? can't you have crouched? can't they have crouched?
V-ing perfect
can't I have been crouching? can't you have been crouching? can't she have been crouching? can't we have been crouching? can't you have been crouching? can't they have been crouching?