could vow
Regular verb: vow - vowed- vowed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could vow
you could vow
he could vow
we could vow
you could vow
they could vow 	I could be vowing
you could be vowing
he could be vowing
we could be vowing
you could be vowing
they could be vowing	I could have vowed
you could have vowed
he could have vowed
we could have vowed
you could have vowed
they could have vowed	I could have been vowing
you could have been vowing
he could have been vowing
we could have been vowing
you could have been vowing
they could have been vowing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't vow
you couldn't vow
he couldn't vow
we couldn't vow
you couldn't vow
they couldn't vow 	I couldn't be vowing
you couldn't be vowing
he couldn't be vowing
we couldn't be vowing
you couldn't be vowing
they couldn't be vowing	I couldn't have vowed
you couldn't have vowed
he couldn't have vowed
we couldn't have vowed
you couldn't have vowed
they couldn't have vowed	I couldn't have been vowing
you couldn't have been vowing
he couldn't have been vowing
we couldn't have been vowing
you couldn't have been vowing
they couldn't have been vowing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I vow?
could you vow?
could he vow?
could we vow?
could you vow?
could they vow? 	could I be vowing?
could you be vowing?
could he be vowing?
could we be vowing?
could you be vowing?
could they be vowing? 	could I have vowed?
could you have vowed?
could he have vowed?
could we have vowed?
could you have vowed?
could they have vowed? 	could I have been vowing?
could you have been vowing?
could he have been vowing?
could we have been vowing?
could you have been vowing?
could they have been vowing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I vow?
couldn't you vow?
couldn't he vow?
couldn't we vow?
couldn't you vow?
couldn't they vow? 	couldn't I be vowing?
couldn't you be vowing?
couldn't he be vowing?
couldn't we be vowing?
couldn't you be vowing?
couldn't they be vowing? 	couldn't I have vowed?
couldn't you have vowed?
couldn't he have vowed?
couldn't we have vowed?
couldn't you have vowed?
couldn't they have vowed? 	couldn't I have been vowing?
couldn't you have been vowing?
couldn't he have been vowing?
couldn't we have been vowing?
couldn't you have been vowing?
couldn't they have been vowing?