could purl
Regular verb: purl - purled- purled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could purl
you could purl
he could purl
we could purl
you could purl
they could purl 	I could be purling
you could be purling
he could be purling
we could be purling
you could be purling
they could be purling	I could have purled
you could have purled
he could have purled
we could have purled
you could have purled
they could have purled	I could have been purling
you could have been purling
he could have been purling
we could have been purling
you could have been purling
they could have been purling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not purl
you could not purl
he could not purl
we could not purl
you could not purl
they could not purl 	I could not be purling
you could not be purling
he could not be purling
we could not be purling
you could not be purling
they could not be purling	I could not have purled
you could not have purled
he could not have purled
we could not have purled
you could not have purled
they could not have purled	I could not have been purling
you could not have been purling
he could not have been purling
we could not have been purling
you could not have been purling
they could not have been purling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I purl?
could you purl?
could he purl?
could we purl?
could you purl?
could they purl? 	could I be purling?
could you be purling?
could he be purling?
could we be purling?
could you be purling?
could they be purling? 	could I have purled?
could you have purled?
could he have purled?
could we have purled?
could you have purled?
could they have purled? 	could I have been purling?
could you have been purling?
could he have been purling?
could we have been purling?
could you have been purling?
could they have been purling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not purl?
could you not purl?
could he not purl?
could we not purl?
could you not purl?
could they not purl? 	could I not be purling?
could you not be purling?
could he not be purling?
could we not be purling?
could you not be purling?
could they not be purling? 	could I not have purled?
could you not have purled?
could he not have purled?
could we not have purled?
could you not have purled?
could they not have purled? 	could I not have been purling?
could you not have been purling?
could he not have been purling?
could we not have been purling?
could you not have been purling?
could they not have been purling?