can whiten
Regular verb: whiten - whitened- whitened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can whiten
you can whiten
she can whiten
we can whiten
you can whiten
they can whiten 	I can be whitening
you can be whitening
she can be whitening
we can be whitening
you can be whitening
they can be whitening	I can have whitened
you can have whitened
she can have whitened
we can have whitened
you can have whitened
they can have whitened	I can have been whitening
you can have been whitening
she can have been whitening
we can have been whitening
you can have been whitening
they can have been whitening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't whiten
you can't whiten
she can't whiten
we can't whiten
you can't whiten
they can't whiten 	I can't be whitening
you can't be whitening
she can't be whitening
we can't be whitening
you can't be whitening
they can't be whitening	I can't have whitened
you can't have whitened
she can't have whitened
we can't have whitened
you can't have whitened
they can't have whitened	I can't have been whitening
you can't have been whitening
she can't have been whitening
we can't have been whitening
you can't have been whitening
they can't have been whitening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I whiten?
can you whiten?
can she whiten?
can we whiten?
can you whiten?
can they whiten? 	can I be whitening?
can you be whitening?
can she be whitening?
can we be whitening?
can you be whitening?
can they be whitening? 	can I have whitened?
can you have whitened?
can she have whitened?
can we have whitened?
can you have whitened?
can they have whitened? 	can I have been whitening?
can you have been whitening?
can she have been whitening?
can we have been whitening?
can you have been whitening?
can they have been whitening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I whiten?
can't you whiten?
can't she whiten?
can't we whiten?
can't you whiten?
can't they whiten? 	can't I be whitening?
can't you be whitening?
can't she be whitening?
can't we be whitening?
can't you be whitening?
can't they be whitening? 	can't I have whitened?
can't you have whitened?
can't she have whitened?
can't we have whitened?
can't you have whitened?
can't they have whitened? 	can't I have been whitening?
can't you have been whitening?
can't she have been whitening?
can't we have been whitening?
can't you have been whitening?
can't they have been whitening?