could polish
Regular verb: polish - polished- polished

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could polish
you could polish
he could polish
we could polish
you could polish
they could polish 	I could be polishing
you could be polishing
he could be polishing
we could be polishing
you could be polishing
they could be polishing	I could have polished
you could have polished
he could have polished
we could have polished
you could have polished
they could have polished	I could have been polishing
you could have been polishing
he could have been polishing
we could have been polishing
you could have been polishing
they could have been polishing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't polish
you couldn't polish
he couldn't polish
we couldn't polish
you couldn't polish
they couldn't polish 	I couldn't be polishing
you couldn't be polishing
he couldn't be polishing
we couldn't be polishing
you couldn't be polishing
they couldn't be polishing	I couldn't have polished
you couldn't have polished
he couldn't have polished
we couldn't have polished
you couldn't have polished
they couldn't have polished	I couldn't have been polishing
you couldn't have been polishing
he couldn't have been polishing
we couldn't have been polishing
you couldn't have been polishing
they couldn't have been polishing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I polish?
could you polish?
could he polish?
could we polish?
could you polish?
could they polish? 	could I be polishing?
could you be polishing?
could he be polishing?
could we be polishing?
could you be polishing?
could they be polishing? 	could I have polished?
could you have polished?
could he have polished?
could we have polished?
could you have polished?
could they have polished? 	could I have been polishing?
could you have been polishing?
could he have been polishing?
could we have been polishing?
could you have been polishing?
could they have been polishing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I polish?
couldn't you polish?
couldn't he polish?
couldn't we polish?
couldn't you polish?
couldn't they polish? 	couldn't I be polishing?
couldn't you be polishing?
couldn't he be polishing?
couldn't we be polishing?
couldn't you be polishing?
couldn't they be polishing? 	couldn't I have polished?
couldn't you have polished?
couldn't he have polished?
couldn't we have polished?
couldn't you have polished?
couldn't they have polished? 	couldn't I have been polishing?
couldn't you have been polishing?
couldn't he have been polishing?
couldn't we have been polishing?
couldn't you have been polishing?
couldn't they have been polishing?