should whiten
Regular verb: whiten - whitened- whitened

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

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should not whiten
you should not whiten
he should not whiten
we should not whiten
you should not whiten
they should not whiten 	I should not be whitening
you should not be whitening
he should not be whitening
we should not be whitening
you should not be whitening
they should not be whitening	I should not have whitened
you should not have whitened
he should not have whitened
we should not have whitened
you should not have whitened
they should not have whitened	I should not have been whitening
you should not have been whitening
he should not have been whitening
we should not have been whitening
you should not have been whitening
they should not have been whitening	

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

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I not whiten?
should you not whiten?
should he not whiten?
should we not whiten?
should you not whiten?
should they not whiten? 	should I not be whitening?
should you not be whitening?
should he not be whitening?
should we not be whitening?
should you not be whitening?
should they not be whitening? 	should I not have whitened?
should you not have whitened?
should he not have whitened?
should we not have whitened?
should you not have whitened?
should they not have whitened? 	should I not have been whitening?
should you not have been whitening?
should he not have been whitening?
should we not have been whitening?
should you not have been whitening?
should they not have been whitening?