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 cannot whiten
you cannot whiten
she cannot whiten
we cannot whiten
you cannot whiten
they cannot whiten 	I cannot be whitening
you cannot be whitening
she cannot be whitening
we cannot be whitening
you cannot be whitening
they cannot be whitening	I cannot have whitened
you cannot have whitened
she cannot have whitened
we cannot have whitened
you cannot have whitened
they cannot have whitened	I cannot have been whitening
you cannot have been whitening
she cannot have been whitening
we cannot have been whitening
you cannot have been whitening
they cannot 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 I not whiten?
can you not whiten?
can she not whiten?
can we not whiten?
can you not whiten?
can they not whiten? 	can I not be whitening?
can you not be whitening?
can she not be whitening?
can we not be whitening?
can you not be whitening?
can they not be whitening? 	can I not have whitened?
can you not have whitened?
can she not have whitened?
can we not have whitened?
can you not have whitened?
can they not have whitened? 	can I not have been whitening?
can you not have been whitening?
can she not have been whitening?
can we not have been whitening?
can you not have been whitening?
can they not have been whitening?