could swallow
Regular verb: swallow - swallowed- swallowed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could swallow
you could swallow
he could swallow
we could swallow
you could swallow
they could swallow 	I could be swallowing
you could be swallowing
he could be swallowing
we could be swallowing
you could be swallowing
they could be swallowing	I could have swallowed
you could have swallowed
he could have swallowed
we could have swallowed
you could have swallowed
they could have swallowed	I could have been swallowing
you could have been swallowing
he could have been swallowing
we could have been swallowing
you could have been swallowing
they could have been swallowing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't swallow
you couldn't swallow
he couldn't swallow
we couldn't swallow
you couldn't swallow
they couldn't swallow 	I couldn't be swallowing
you couldn't be swallowing
he couldn't be swallowing
we couldn't be swallowing
you couldn't be swallowing
they couldn't be swallowing	I couldn't have swallowed
you couldn't have swallowed
he couldn't have swallowed
we couldn't have swallowed
you couldn't have swallowed
they couldn't have swallowed	I couldn't have been swallowing
you couldn't have been swallowing
he couldn't have been swallowing
we couldn't have been swallowing
you couldn't have been swallowing
they couldn't have been swallowing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I swallow?
could you swallow?
could he swallow?
could we swallow?
could you swallow?
could they swallow? 	could I be swallowing?
could you be swallowing?
could he be swallowing?
could we be swallowing?
could you be swallowing?
could they be swallowing? 	could I have swallowed?
could you have swallowed?
could he have swallowed?
could we have swallowed?
could you have swallowed?
could they have swallowed? 	could I have been swallowing?
could you have been swallowing?
could he have been swallowing?
could we have been swallowing?
could you have been swallowing?
could they have been swallowing? 	

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