could sheave
Regular verb: sheave - sheaved- sheaved

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could sheave
you could sheave
she could sheave
we could sheave
you could sheave
they could sheave 	I could be sheaving
you could be sheaving
she could be sheaving
we could be sheaving
you could be sheaving
they could be sheaving	I could have sheaved
you could have sheaved
she could have sheaved
we could have sheaved
you could have sheaved
they could have sheaved	I could have been sheaving
you could have been sheaving
she could have been sheaving
we could have been sheaving
you could have been sheaving
they could have been sheaving	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't sheave
you couldn't sheave
she couldn't sheave
we couldn't sheave
you couldn't sheave
they couldn't sheave 	I couldn't be sheaving
you couldn't be sheaving
she couldn't be sheaving
we couldn't be sheaving
you couldn't be sheaving
they couldn't be sheaving	I couldn't have sheaved
you couldn't have sheaved
she couldn't have sheaved
we couldn't have sheaved
you couldn't have sheaved
they couldn't have sheaved	I couldn't have been sheaving
you couldn't have been sheaving
she couldn't have been sheaving
we couldn't have been sheaving
you couldn't have been sheaving
they couldn't have been sheaving	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I sheave?
could you sheave?
could she sheave?
could we sheave?
could you sheave?
could they sheave? 	could I be sheaving?
could you be sheaving?
could she be sheaving?
could we be sheaving?
could you be sheaving?
could they be sheaving? 	could I have sheaved?
could you have sheaved?
could she have sheaved?
could we have sheaved?
could you have sheaved?
could they have sheaved? 	could I have been sheaving?
could you have been sheaving?
could she have been sheaving?
could we have been sheaving?
could you have been sheaving?
could they have been sheaving? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I sheave?
couldn't you sheave?
couldn't she sheave?
couldn't we sheave?
couldn't you sheave?
couldn't they sheave? 	couldn't I be sheaving?
couldn't you be sheaving?
couldn't she be sheaving?
couldn't we be sheaving?
couldn't you be sheaving?
couldn't they be sheaving? 	couldn't I have sheaved?
couldn't you have sheaved?
couldn't she have sheaved?
couldn't we have sheaved?
couldn't you have sheaved?
couldn't they have sheaved? 	couldn't I have been sheaving?
couldn't you have been sheaving?
couldn't she have been sheaving?
couldn't we have been sheaving?
couldn't you have been sheaving?
couldn't they have been sheaving?