could shingle
Regular verb: shingle - shingled- shingled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could shingle
you could shingle
he could shingle
we could shingle
you could shingle
they could shingle 	I could be shingling
you could be shingling
he could be shingling
we could be shingling
you could be shingling
they could be shingling	I could have shingled
you could have shingled
he could have shingled
we could have shingled
you could have shingled
they could have shingled	I could have been shingling
you could have been shingling
he could have been shingling
we could have been shingling
you could have been shingling
they could have been shingling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not shingle
you could not shingle
he could not shingle
we could not shingle
you could not shingle
they could not shingle 	I could not be shingling
you could not be shingling
he could not be shingling
we could not be shingling
you could not be shingling
they could not be shingling	I could not have shingled
you could not have shingled
he could not have shingled
we could not have shingled
you could not have shingled
they could not have shingled	I could not have been shingling
you could not have been shingling
he could not have been shingling
we could not have been shingling
you could not have been shingling
they could not have been shingling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I shingle?
could you shingle?
could he shingle?
could we shingle?
could you shingle?
could they shingle? 	could I be shingling?
could you be shingling?
could he be shingling?
could we be shingling?
could you be shingling?
could they be shingling? 	could I have shingled?
could you have shingled?
could he have shingled?
could we have shingled?
could you have shingled?
could they have shingled? 	could I have been shingling?
could you have been shingling?
could he have been shingling?
could we have been shingling?
could you have been shingling?
could they have been shingling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not shingle?
could you not shingle?
could he not shingle?
could we not shingle?
could you not shingle?
could they not shingle? 	could I not be shingling?
could you not be shingling?
could he not be shingling?
could we not be shingling?
could you not be shingling?
could they not be shingling? 	could I not have shingled?
could you not have shingled?
could he not have shingled?
could we not have shingled?
could you not have shingled?
could they not have shingled? 	could I not have been shingling?
could you not have been shingling?
could he not have been shingling?
could we not have been shingling?
could you not have been shingling?
could they not have been shingling?