can invalidate
Regular verb: invalidate - invalidated- invalidated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can invalidate
you can invalidate
she can invalidate
we can invalidate
you can invalidate
they can invalidate 	I can be invalidating
you can be invalidating
she can be invalidating
we can be invalidating
you can be invalidating
they can be invalidating	I can have invalidated
you can have invalidated
she can have invalidated
we can have invalidated
you can have invalidated
they can have invalidated	I can have been invalidating
you can have been invalidating
she can have been invalidating
we can have been invalidating
you can have been invalidating
they can have been invalidating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't invalidate
you can't invalidate
she can't invalidate
we can't invalidate
you can't invalidate
they can't invalidate 	I can't be invalidating
you can't be invalidating
she can't be invalidating
we can't be invalidating
you can't be invalidating
they can't be invalidating	I can't have invalidated
you can't have invalidated
she can't have invalidated
we can't have invalidated
you can't have invalidated
they can't have invalidated	I can't have been invalidating
you can't have been invalidating
she can't have been invalidating
we can't have been invalidating
you can't have been invalidating
they can't have been invalidating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I invalidate?
can you invalidate?
can she invalidate?
can we invalidate?
can you invalidate?
can they invalidate? 	can I be invalidating?
can you be invalidating?
can she be invalidating?
can we be invalidating?
can you be invalidating?
can they be invalidating? 	can I have invalidated?
can you have invalidated?
can she have invalidated?
can we have invalidated?
can you have invalidated?
can they have invalidated? 	can I have been invalidating?
can you have been invalidating?
can she have been invalidating?
can we have been invalidating?
can you have been invalidating?
can they have been invalidating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I invalidate?
can't you invalidate?
can't she invalidate?
can't we invalidate?
can't you invalidate?
can't they invalidate? 	can't I be invalidating?
can't you be invalidating?
can't she be invalidating?
can't we be invalidating?
can't you be invalidating?
can't they be invalidating? 	can't I have invalidated?
can't you have invalidated?
can't she have invalidated?
can't we have invalidated?
can't you have invalidated?
can't they have invalidated? 	can't I have been invalidating?
can't you have been invalidating?
can't she have been invalidating?
can't we have been invalidating?
can't you have been invalidating?
can't they have been invalidating?