could skin
Regular verb: skin - skinned- skinned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could skin
you could skin
he could skin
we could skin
you could skin
they could skin 	I could be skinning
you could be skinning
he could be skinning
we could be skinning
you could be skinning
they could be skinning	I could have skinned
you could have skinned
he could have skinned
we could have skinned
you could have skinned
they could have skinned	I could have been skinning
you could have been skinning
he could have been skinning
we could have been skinning
you could have been skinning
they could have been skinning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't skin
you couldn't skin
he couldn't skin
we couldn't skin
you couldn't skin
they couldn't skin 	I couldn't be skinning
you couldn't be skinning
he couldn't be skinning
we couldn't be skinning
you couldn't be skinning
they couldn't be skinning	I couldn't have skinned
you couldn't have skinned
he couldn't have skinned
we couldn't have skinned
you couldn't have skinned
they couldn't have skinned	I couldn't have been skinning
you couldn't have been skinning
he couldn't have been skinning
we couldn't have been skinning
you couldn't have been skinning
they couldn't have been skinning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I skin?
could you skin?
could he skin?
could we skin?
could you skin?
could they skin? 	could I be skinning?
could you be skinning?
could he be skinning?
could we be skinning?
could you be skinning?
could they be skinning? 	could I have skinned?
could you have skinned?
could he have skinned?
could we have skinned?
could you have skinned?
could they have skinned? 	could I have been skinning?
could you have been skinning?
could he have been skinning?
could we have been skinning?
could you have been skinning?
could they have been skinning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I skin?
couldn't you skin?
couldn't he skin?
couldn't we skin?
couldn't you skin?
couldn't they skin? 	couldn't I be skinning?
couldn't you be skinning?
couldn't he be skinning?
couldn't we be skinning?
couldn't you be skinning?
couldn't they be skinning? 	couldn't I have skinned?
couldn't you have skinned?
couldn't he have skinned?
couldn't we have skinned?
couldn't you have skinned?
couldn't they have skinned? 	couldn't I have been skinning?
couldn't you have been skinning?
couldn't he have been skinning?
couldn't we have been skinning?
couldn't you have been skinning?
couldn't they have been skinning?