could yelp
Regular verb: yelp - yelped- yelped

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could yelp
you could yelp
she could yelp
we could yelp
you could yelp
they could yelp 	I could be yelping
you could be yelping
she could be yelping
we could be yelping
you could be yelping
they could be yelping	I could have yelped
you could have yelped
she could have yelped
we could have yelped
you could have yelped
they could have yelped	I could have been yelping
you could have been yelping
she could have been yelping
we could have been yelping
you could have been yelping
they could have been yelping	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't yelp
you couldn't yelp
she couldn't yelp
we couldn't yelp
you couldn't yelp
they couldn't yelp 	I couldn't be yelping
you couldn't be yelping
she couldn't be yelping
we couldn't be yelping
you couldn't be yelping
they couldn't be yelping	I couldn't have yelped
you couldn't have yelped
she couldn't have yelped
we couldn't have yelped
you couldn't have yelped
they couldn't have yelped	I couldn't have been yelping
you couldn't have been yelping
she couldn't have been yelping
we couldn't have been yelping
you couldn't have been yelping
they couldn't have been yelping	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I yelp?
could you yelp?
could she yelp?
could we yelp?
could you yelp?
could they yelp? 	could I be yelping?
could you be yelping?
could she be yelping?
could we be yelping?
could you be yelping?
could they be yelping? 	could I have yelped?
could you have yelped?
could she have yelped?
could we have yelped?
could you have yelped?
could they have yelped? 	could I have been yelping?
could you have been yelping?
could she have been yelping?
could we have been yelping?
could you have been yelping?
could they have been yelping? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I yelp?
couldn't you yelp?
couldn't she yelp?
couldn't we yelp?
couldn't you yelp?
couldn't they yelp? 	couldn't I be yelping?
couldn't you be yelping?
couldn't she be yelping?
couldn't we be yelping?
couldn't you be yelping?
couldn't they be yelping? 	couldn't I have yelped?
couldn't you have yelped?
couldn't she have yelped?
couldn't we have yelped?
couldn't you have yelped?
couldn't they have yelped? 	couldn't I have been yelping?
couldn't you have been yelping?
couldn't she have been yelping?
couldn't we have been yelping?
couldn't you have been yelping?
couldn't they have been yelping?