could dust
Regular verb: dust - dusted- dusted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could dust
you could dust
he could dust
we could dust
you could dust
they could dust 	I could be dusting
you could be dusting
he could be dusting
we could be dusting
you could be dusting
they could be dusting	I could have dusted
you could have dusted
he could have dusted
we could have dusted
you could have dusted
they could have dusted	I could have been dusting
you could have been dusting
he could have been dusting
we could have been dusting
you could have been dusting
they could have been dusting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not dust
you could not dust
he could not dust
we could not dust
you could not dust
they could not dust 	I could not be dusting
you could not be dusting
he could not be dusting
we could not be dusting
you could not be dusting
they could not be dusting	I could not have dusted
you could not have dusted
he could not have dusted
we could not have dusted
you could not have dusted
they could not have dusted	I could not have been dusting
you could not have been dusting
he could not have been dusting
we could not have been dusting
you could not have been dusting
they could not have been dusting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I dust?
could you dust?
could he dust?
could we dust?
could you dust?
could they dust? 	could I be dusting?
could you be dusting?
could he be dusting?
could we be dusting?
could you be dusting?
could they be dusting? 	could I have dusted?
could you have dusted?
could he have dusted?
could we have dusted?
could you have dusted?
could they have dusted? 	could I have been dusting?
could you have been dusting?
could he have been dusting?
could we have been dusting?
could you have been dusting?
could they have been dusting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not dust?
could you not dust?
could he not dust?
could we not dust?
could you not dust?
could they not dust? 	could I not be dusting?
could you not be dusting?
could he not be dusting?
could we not be dusting?
could you not be dusting?
could they not be dusting? 	could I not have dusted?
could you not have dusted?
could he not have dusted?
could we not have dusted?
could you not have dusted?
could they not have dusted? 	could I not have been dusting?
could you not have been dusting?
could he not have been dusting?
could we not have been dusting?
could you not have been dusting?
could they not have been dusting?