can harden
Regular verb: harden - hardened- hardened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can harden
you can harden
he can harden
we can harden
you can harden
they can harden 	I can be hardening
you can be hardening
he can be hardening
we can be hardening
you can be hardening
they can be hardening	I can have hardened
you can have hardened
he can have hardened
we can have hardened
you can have hardened
they can have hardened	I can have been hardening
you can have been hardening
he can have been hardening
we can have been hardening
you can have been hardening
they can have been hardening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't harden
you can't harden
he can't harden
we can't harden
you can't harden
they can't harden 	I can't be hardening
you can't be hardening
he can't be hardening
we can't be hardening
you can't be hardening
they can't be hardening	I can't have hardened
you can't have hardened
he can't have hardened
we can't have hardened
you can't have hardened
they can't have hardened	I can't have been hardening
you can't have been hardening
he can't have been hardening
we can't have been hardening
you can't have been hardening
they can't have been hardening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I harden?
can you harden?
can he harden?
can we harden?
can you harden?
can they harden? 	can I be hardening?
can you be hardening?
can he be hardening?
can we be hardening?
can you be hardening?
can they be hardening? 	can I have hardened?
can you have hardened?
can he have hardened?
can we have hardened?
can you have hardened?
can they have hardened? 	can I have been hardening?
can you have been hardening?
can he have been hardening?
can we have been hardening?
can you have been hardening?
can they have been hardening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I harden?
can't you harden?
can't he harden?
can't we harden?
can't you harden?
can't they harden? 	can't I be hardening?
can't you be hardening?
can't he be hardening?
can't we be hardening?
can't you be hardening?
can't they be hardening? 	can't I have hardened?
can't you have hardened?
can't he have hardened?
can't we have hardened?
can't you have hardened?
can't they have hardened? 	can't I have been hardening?
can't you have been hardening?
can't he have been hardening?
can't we have been hardening?
can't you have been hardening?
can't they have been hardening?