could whitewash
Regular verb: whitewash - whitewashed- whitewashed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could whitewash
you could whitewash
he could whitewash
we could whitewash
you could whitewash
they could whitewash 	I could be whitewashing
you could be whitewashing
he could be whitewashing
we could be whitewashing
you could be whitewashing
they could be whitewashing	I could have whitewashed
you could have whitewashed
he could have whitewashed
we could have whitewashed
you could have whitewashed
they could have whitewashed	I could have been whitewashing
you could have been whitewashing
he could have been whitewashing
we could have been whitewashing
you could have been whitewashing
they could have been whitewashing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't whitewash
you couldn't whitewash
he couldn't whitewash
we couldn't whitewash
you couldn't whitewash
they couldn't whitewash 	I couldn't be whitewashing
you couldn't be whitewashing
he couldn't be whitewashing
we couldn't be whitewashing
you couldn't be whitewashing
they couldn't be whitewashing	I couldn't have whitewashed
you couldn't have whitewashed
he couldn't have whitewashed
we couldn't have whitewashed
you couldn't have whitewashed
they couldn't have whitewashed	I couldn't have been whitewashing
you couldn't have been whitewashing
he couldn't have been whitewashing
we couldn't have been whitewashing
you couldn't have been whitewashing
they couldn't have been whitewashing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I whitewash?
could you whitewash?
could he whitewash?
could we whitewash?
could you whitewash?
could they whitewash? 	could I be whitewashing?
could you be whitewashing?
could he be whitewashing?
could we be whitewashing?
could you be whitewashing?
could they be whitewashing? 	could I have whitewashed?
could you have whitewashed?
could he have whitewashed?
could we have whitewashed?
could you have whitewashed?
could they have whitewashed? 	could I have been whitewashing?
could you have been whitewashing?
could he have been whitewashing?
could we have been whitewashing?
could you have been whitewashing?
could they have been whitewashing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I whitewash?
couldn't you whitewash?
couldn't he whitewash?
couldn't we whitewash?
couldn't you whitewash?
couldn't they whitewash? 	couldn't I be whitewashing?
couldn't you be whitewashing?
couldn't he be whitewashing?
couldn't we be whitewashing?
couldn't you be whitewashing?
couldn't they be whitewashing? 	couldn't I have whitewashed?
couldn't you have whitewashed?
couldn't he have whitewashed?
couldn't we have whitewashed?
couldn't you have whitewashed?
couldn't they have whitewashed? 	couldn't I have been whitewashing?
couldn't you have been whitewashing?
couldn't he have been whitewashing?
couldn't we have been whitewashing?
couldn't you have been whitewashing?
couldn't they have been whitewashing?