could vex
Regular verb: vex - vexed- vexed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could vex
you could vex
he could vex
we could vex
you could vex
they could vex 	I could be vexing
you could be vexing
he could be vexing
we could be vexing
you could be vexing
they could be vexing	I could have vexed
you could have vexed
he could have vexed
we could have vexed
you could have vexed
they could have vexed	I could have been vexing
you could have been vexing
he could have been vexing
we could have been vexing
you could have been vexing
they could have been vexing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't vex
you couldn't vex
he couldn't vex
we couldn't vex
you couldn't vex
they couldn't vex 	I couldn't be vexing
you couldn't be vexing
he couldn't be vexing
we couldn't be vexing
you couldn't be vexing
they couldn't be vexing	I couldn't have vexed
you couldn't have vexed
he couldn't have vexed
we couldn't have vexed
you couldn't have vexed
they couldn't have vexed	I couldn't have been vexing
you couldn't have been vexing
he couldn't have been vexing
we couldn't have been vexing
you couldn't have been vexing
they couldn't have been vexing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I vex?
could you vex?
could he vex?
could we vex?
could you vex?
could they vex? 	could I be vexing?
could you be vexing?
could he be vexing?
could we be vexing?
could you be vexing?
could they be vexing? 	could I have vexed?
could you have vexed?
could he have vexed?
could we have vexed?
could you have vexed?
could they have vexed? 	could I have been vexing?
could you have been vexing?
could he have been vexing?
could we have been vexing?
could you have been vexing?
could they have been vexing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I vex?
couldn't you vex?
couldn't he vex?
couldn't we vex?
couldn't you vex?
couldn't they vex? 	couldn't I be vexing?
couldn't you be vexing?
couldn't he be vexing?
couldn't we be vexing?
couldn't you be vexing?
couldn't they be vexing? 	couldn't I have vexed?
couldn't you have vexed?
couldn't he have vexed?
couldn't we have vexed?
couldn't you have vexed?
couldn't they have vexed? 	couldn't I have been vexing?
couldn't you have been vexing?
couldn't he have been vexing?
couldn't we have been vexing?
couldn't you have been vexing?
couldn't they have been vexing?