I can swallow you can swallow he can swallow we can swallow you can swallow they can swallow
V-ing form
I can be swallowing you can be swallowing he can be swallowing we can be swallowing you can be swallowing they can be swallowing
Perfect
I can have swallowed you can have swallowed he can have swallowed we can have swallowed you can have swallowed they can have swallowed
V-ing perfect
I can have been swallowing you can have been swallowing he can have been swallowing we can have been swallowing you can have been swallowing they can have been swallowing
Negation
Simple form
I can't swallow you can't swallow he can't swallow we can't swallow you can't swallow they can't swallow
V-ing form
I can't be swallowing you can't be swallowing he can't be swallowing we can't be swallowing you can't be swallowing they can't be swallowing
Perfect
I can't have swallowed you can't have swallowed he can't have swallowed we can't have swallowed you can't have swallowed they can't have swallowed
V-ing perfect
I can't have been swallowing you can't have been swallowing he can't have been swallowing we can't have been swallowing you can't have been swallowing they can't have been swallowing
Interrogative form
Simple form
can I swallow? can you swallow? can he swallow? can we swallow? can you swallow? can they swallow?
V-ing form
can I be swallowing? can you be swallowing? can he be swallowing? can we be swallowing? can you be swallowing? can they be swallowing?
Perfect
can I have swallowed? can you have swallowed? can he have swallowed? can we have swallowed? can you have swallowed? can they have swallowed?
V-ing perfect
can I have been swallowing? can you have been swallowing? can he have been swallowing? can we have been swallowing? can you have been swallowing? can they have been swallowing?
Interro-negative form
Simple form
can't I swallow? can't you swallow? can't he swallow? can't we swallow? can't you swallow? can't they swallow?
V-ing form
can't I be swallowing? can't you be swallowing? can't he be swallowing? can't we be swallowing? can't you be swallowing? can't they be swallowing?
Perfect
can't I have swallowed? can't you have swallowed? can't he have swallowed? can't we have swallowed? can't you have swallowed? can't they have swallowed?
V-ing perfect
can't I have been swallowing? can't you have been swallowing? can't he have been swallowing? can't we have been swallowing? can't you have been swallowing? can't they have been swallowing?