can impair
Regular verb: impair - impaired- impaired

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can impair
you can impair
he can impair
we can impair
you can impair
they can impair 	I can be impairing
you can be impairing
he can be impairing
we can be impairing
you can be impairing
they can be impairing	I can have impaired
you can have impaired
he can have impaired
we can have impaired
you can have impaired
they can have impaired	I can have been impairing
you can have been impairing
he can have been impairing
we can have been impairing
you can have been impairing
they can have been impairing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't impair
you can't impair
he can't impair
we can't impair
you can't impair
they can't impair 	I can't be impairing
you can't be impairing
he can't be impairing
we can't be impairing
you can't be impairing
they can't be impairing	I can't have impaired
you can't have impaired
he can't have impaired
we can't have impaired
you can't have impaired
they can't have impaired	I can't have been impairing
you can't have been impairing
he can't have been impairing
we can't have been impairing
you can't have been impairing
they can't have been impairing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I impair?
can you impair?
can he impair?
can we impair?
can you impair?
can they impair? 	can I be impairing?
can you be impairing?
can he be impairing?
can we be impairing?
can you be impairing?
can they be impairing? 	can I have impaired?
can you have impaired?
can he have impaired?
can we have impaired?
can you have impaired?
can they have impaired? 	can I have been impairing?
can you have been impairing?
can he have been impairing?
can we have been impairing?
can you have been impairing?
can they have been impairing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I impair?
can't you impair?
can't he impair?
can't we impair?
can't you impair?
can't they impair? 	can't I be impairing?
can't you be impairing?
can't he be impairing?
can't we be impairing?
can't you be impairing?
can't they be impairing? 	can't I have impaired?
can't you have impaired?
can't he have impaired?
can't we have impaired?
can't you have impaired?
can't they have impaired? 	can't I have been impairing?
can't you have been impairing?
can't he have been impairing?
can't we have been impairing?
can't you have been impairing?
can't they have been impairing?