could soften
Regular verb: soften - softened- softened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could soften
you could soften
he could soften
we could soften
you could soften
they could soften 	I could be softening
you could be softening
he could be softening
we could be softening
you could be softening
they could be softening	I could have softened
you could have softened
he could have softened
we could have softened
you could have softened
they could have softened	I could have been softening
you could have been softening
he could have been softening
we could have been softening
you could have been softening
they could have been softening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't soften
you couldn't soften
he couldn't soften
we couldn't soften
you couldn't soften
they couldn't soften 	I couldn't be softening
you couldn't be softening
he couldn't be softening
we couldn't be softening
you couldn't be softening
they couldn't be softening	I couldn't have softened
you couldn't have softened
he couldn't have softened
we couldn't have softened
you couldn't have softened
they couldn't have softened	I couldn't have been softening
you couldn't have been softening
he couldn't have been softening
we couldn't have been softening
you couldn't have been softening
they couldn't have been softening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I soften?
could you soften?
could he soften?
could we soften?
could you soften?
could they soften? 	could I be softening?
could you be softening?
could he be softening?
could we be softening?
could you be softening?
could they be softening? 	could I have softened?
could you have softened?
could he have softened?
could we have softened?
could you have softened?
could they have softened? 	could I have been softening?
could you have been softening?
could he have been softening?
could we have been softening?
could you have been softening?
could they have been softening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I soften?
couldn't you soften?
couldn't he soften?
couldn't we soften?
couldn't you soften?
couldn't they soften? 	couldn't I be softening?
couldn't you be softening?
couldn't he be softening?
couldn't we be softening?
couldn't you be softening?
couldn't they be softening? 	couldn't I have softened?
couldn't you have softened?
couldn't he have softened?
couldn't we have softened?
couldn't you have softened?
couldn't they have softened? 	couldn't I have been softening?
couldn't you have been softening?
couldn't he have been softening?
couldn't we have been softening?
couldn't you have been softening?
couldn't they have been softening?