can preharden
Regular verb: preharden - prehardened- prehardened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can preharden
you can preharden
he can preharden
we can preharden
you can preharden
they can preharden 	I can be prehardening
you can be prehardening
he can be prehardening
we can be prehardening
you can be prehardening
they can be prehardening	I can have prehardened
you can have prehardened
he can have prehardened
we can have prehardened
you can have prehardened
they can have prehardened	I can have been prehardening
you can have been prehardening
he can have been prehardening
we can have been prehardening
you can have been prehardening
they can have been prehardening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot preharden
you cannot preharden
he cannot preharden
we cannot preharden
you cannot preharden
they cannot preharden 	I cannot be prehardening
you cannot be prehardening
he cannot be prehardening
we cannot be prehardening
you cannot be prehardening
they cannot be prehardening	I cannot have prehardened
you cannot have prehardened
he cannot have prehardened
we cannot have prehardened
you cannot have prehardened
they cannot have prehardened	I cannot have been prehardening
you cannot have been prehardening
he cannot have been prehardening
we cannot have been prehardening
you cannot have been prehardening
they cannot have been prehardening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I preharden?
can you preharden?
can he preharden?
can we preharden?
can you preharden?
can they preharden? 	can I be prehardening?
can you be prehardening?
can he be prehardening?
can we be prehardening?
can you be prehardening?
can they be prehardening? 	can I have prehardened?
can you have prehardened?
can he have prehardened?
can we have prehardened?
can you have prehardened?
can they have prehardened? 	can I have been prehardening?
can you have been prehardening?
can he have been prehardening?
can we have been prehardening?
can you have been prehardening?
can they have been prehardening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not preharden?
can you not preharden?
can he not preharden?
can we not preharden?
can you not preharden?
can they not preharden? 	can I not be prehardening?
can you not be prehardening?
can he not be prehardening?
can we not be prehardening?
can you not be prehardening?
can they not be prehardening? 	can I not have prehardened?
can you not have prehardened?
can he not have prehardened?
can we not have prehardened?
can you not have prehardened?
can they not have prehardened? 	can I not have been prehardening?
can you not have been prehardening?
can he not have been prehardening?
can we not have been prehardening?
can you not have been prehardening?
can they not have been prehardening?