I can worry you can worry he can worry we can worry you can worry they can worry
V-ing form
I can be worrying you can be worrying he can be worrying we can be worrying you can be worrying they can be worrying
Perfect
I can have worried you can have worried he can have worried we can have worried you can have worried they can have worried
V-ing perfect
I can have been worrying you can have been worrying he can have been worrying we can have been worrying you can have been worrying they can have been worrying
Negation
Simple form
I can't worry you can't worry he can't worry we can't worry you can't worry they can't worry
V-ing form
I can't be worrying you can't be worrying he can't be worrying we can't be worrying you can't be worrying they can't be worrying
Perfect
I can't have worried you can't have worried he can't have worried we can't have worried you can't have worried they can't have worried
V-ing perfect
I can't have been worrying you can't have been worrying he can't have been worrying we can't have been worrying you can't have been worrying they can't have been worrying
Interrogative form
Simple form
can I worry? can you worry? can he worry? can we worry? can you worry? can they worry?
V-ing form
can I be worrying? can you be worrying? can he be worrying? can we be worrying? can you be worrying? can they be worrying?
Perfect
can I have worried? can you have worried? can he have worried? can we have worried? can you have worried? can they have worried?
V-ing perfect
can I have been worrying? can you have been worrying? can he have been worrying? can we have been worrying? can you have been worrying? can they have been worrying?
Interro-negative form
Simple form
can't I worry? can't you worry? can't he worry? can't we worry? can't you worry? can't they worry?
V-ing form
can't I be worrying? can't you be worrying? can't he be worrying? can't we be worrying? can't you be worrying? can't they be worrying?
Perfect
can't I have worried? can't you have worried? can't he have worried? can't we have worried? can't you have worried? can't they have worried?
V-ing perfect
can't I have been worrying? can't you have been worrying? can't he have been worrying? can't we have been worrying? can't you have been worrying? can't they have been worrying?