could silk
Regular verb: silk - silked- silked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could silk
you could silk
he could silk
we could silk
you could silk
they could silk 	I could be silking
you could be silking
he could be silking
we could be silking
you could be silking
they could be silking	I could have silked
you could have silked
he could have silked
we could have silked
you could have silked
they could have silked	I could have been silking
you could have been silking
he could have been silking
we could have been silking
you could have been silking
they could have been silking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't silk
you couldn't silk
he couldn't silk
we couldn't silk
you couldn't silk
they couldn't silk 	I couldn't be silking
you couldn't be silking
he couldn't be silking
we couldn't be silking
you couldn't be silking
they couldn't be silking	I couldn't have silked
you couldn't have silked
he couldn't have silked
we couldn't have silked
you couldn't have silked
they couldn't have silked	I couldn't have been silking
you couldn't have been silking
he couldn't have been silking
we couldn't have been silking
you couldn't have been silking
they couldn't have been silking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I silk?
could you silk?
could he silk?
could we silk?
could you silk?
could they silk? 	could I be silking?
could you be silking?
could he be silking?
could we be silking?
could you be silking?
could they be silking? 	could I have silked?
could you have silked?
could he have silked?
could we have silked?
could you have silked?
could they have silked? 	could I have been silking?
could you have been silking?
could he have been silking?
could we have been silking?
could you have been silking?
could they have been silking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I silk?
couldn't you silk?
couldn't he silk?
couldn't we silk?
couldn't you silk?
couldn't they silk? 	couldn't I be silking?
couldn't you be silking?
couldn't he be silking?
couldn't we be silking?
couldn't you be silking?
couldn't they be silking? 	couldn't I have silked?
couldn't you have silked?
couldn't he have silked?
couldn't we have silked?
couldn't you have silked?
couldn't they have silked? 	couldn't I have been silking?
couldn't you have been silking?
couldn't he have been silking?
couldn't we have been silking?
couldn't you have been silking?
couldn't they have been silking?