could harken
Regular verb: harken - harkened- harkened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could harken
you could harken
he could harken
we could harken
you could harken
they could harken 	I could be harkening
you could be harkening
he could be harkening
we could be harkening
you could be harkening
they could be harkening	I could have harkened
you could have harkened
he could have harkened
we could have harkened
you could have harkened
they could have harkened	I could have been harkening
you could have been harkening
he could have been harkening
we could have been harkening
you could have been harkening
they could have been harkening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't harken
you couldn't harken
he couldn't harken
we couldn't harken
you couldn't harken
they couldn't harken 	I couldn't be harkening
you couldn't be harkening
he couldn't be harkening
we couldn't be harkening
you couldn't be harkening
they couldn't be harkening	I couldn't have harkened
you couldn't have harkened
he couldn't have harkened
we couldn't have harkened
you couldn't have harkened
they couldn't have harkened	I couldn't have been harkening
you couldn't have been harkening
he couldn't have been harkening
we couldn't have been harkening
you couldn't have been harkening
they couldn't have been harkening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I harken?
could you harken?
could he harken?
could we harken?
could you harken?
could they harken? 	could I be harkening?
could you be harkening?
could he be harkening?
could we be harkening?
could you be harkening?
could they be harkening? 	could I have harkened?
could you have harkened?
could he have harkened?
could we have harkened?
could you have harkened?
could they have harkened? 	could I have been harkening?
could you have been harkening?
could he have been harkening?
could we have been harkening?
could you have been harkening?
could they have been harkening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I harken?
couldn't you harken?
couldn't he harken?
couldn't we harken?
couldn't you harken?
couldn't they harken? 	couldn't I be harkening?
couldn't you be harkening?
couldn't he be harkening?
couldn't we be harkening?
couldn't you be harkening?
couldn't they be harkening? 	couldn't I have harkened?
couldn't you have harkened?
couldn't he have harkened?
couldn't we have harkened?
couldn't you have harkened?
couldn't they have harkened? 	couldn't I have been harkening?
couldn't you have been harkening?
couldn't he have been harkening?
couldn't we have been harkening?
couldn't you have been harkening?
couldn't they have been harkening?