could yield
Regular verb: yield - yielded- yielded

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could yield
you could yield
she could yield
we could yield
you could yield
they could yield 	I could be yielding
you could be yielding
she could be yielding
we could be yielding
you could be yielding
they could be yielding	I could have yielded
you could have yielded
she could have yielded
we could have yielded
you could have yielded
they could have yielded	I could have been yielding
you could have been yielding
she could have been yielding
we could have been yielding
you could have been yielding
they could have been yielding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't yield
you couldn't yield
she couldn't yield
we couldn't yield
you couldn't yield
they couldn't yield 	I couldn't be yielding
you couldn't be yielding
she couldn't be yielding
we couldn't be yielding
you couldn't be yielding
they couldn't be yielding	I couldn't have yielded
you couldn't have yielded
she couldn't have yielded
we couldn't have yielded
you couldn't have yielded
they couldn't have yielded	I couldn't have been yielding
you couldn't have been yielding
she couldn't have been yielding
we couldn't have been yielding
you couldn't have been yielding
they couldn't have been yielding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I yield?
could you yield?
could she yield?
could we yield?
could you yield?
could they yield? 	could I be yielding?
could you be yielding?
could she be yielding?
could we be yielding?
could you be yielding?
could they be yielding? 	could I have yielded?
could you have yielded?
could she have yielded?
could we have yielded?
could you have yielded?
could they have yielded? 	could I have been yielding?
could you have been yielding?
could she have been yielding?
could we have been yielding?
could you have been yielding?
could they have been yielding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I yield?
couldn't you yield?
couldn't she yield?
couldn't we yield?
couldn't you yield?
couldn't they yield? 	couldn't I be yielding?
couldn't you be yielding?
couldn't she be yielding?
couldn't we be yielding?
couldn't you be yielding?
couldn't they be yielding? 	couldn't I have yielded?
couldn't you have yielded?
couldn't she have yielded?
couldn't we have yielded?
couldn't you have yielded?
couldn't they have yielded? 	couldn't I have been yielding?
couldn't you have been yielding?
couldn't she have been yielding?
couldn't we have been yielding?
couldn't you have been yielding?
couldn't they have been yielding?