English verb conjugation
COULD UNBUCKLE

Regular verb: unbuckle - unbuckled - unbuckled

Affirmation

Simple form	V-ing form
I could unbuckle you could unbuckle he could unbuckle we could unbuckle you could unbuckle they could unbuckle	I could be unbuckling you could be unbuckling he could be unbuckling we could be unbuckling you could be unbuckling they could be unbuckling
Perfect	V-ing perfect
I could have unbuckled you could have unbuckled he could have unbuckled we could have unbuckled you could have unbuckled they could have unbuckled	I could have been unbuckling you could have been unbuckling he could have been unbuckling we could have been unbuckling you could have been unbuckling they could have been unbuckling

Negation

Simple form	V-ing form
I couldn't unbuckle you couldn't unbuckle he couldn't unbuckle we couldn't unbuckle you couldn't unbuckle they couldn't unbuckle	I couldn't be unbuckling you couldn't be unbuckling he couldn't be unbuckling we couldn't be unbuckling you couldn't be unbuckling they couldn't be unbuckling
Perfect	V-ing perfect
I couldn't have unbuckled you couldn't have unbuckled he couldn't have unbuckled we couldn't have unbuckled you couldn't have unbuckled they couldn't have unbuckled	I couldn't have been unbuckling you couldn't have been unbuckling he couldn't have been unbuckling we couldn't have been unbuckling you couldn't have been unbuckling they couldn't have been unbuckling

Interrogative form

Simple form	V-ing form
could I unbuckle? could you unbuckle? could he unbuckle? could we unbuckle? could you unbuckle? could they unbuckle?	could I be unbuckling? could you be unbuckling? could he be unbuckling? could we be unbuckling? could you be unbuckling? could they be unbuckling?
Perfect	V-ing perfect
could I have unbuckled? could you have unbuckled? could he have unbuckled? could we have unbuckled? could you have unbuckled? could they have unbuckled?	could I have been unbuckling? could you have been unbuckling? could he have been unbuckling? could we have been unbuckling? could you have been unbuckling? could they have been unbuckling?

Interro-negative form

Simple form	V-ing form
couldn't I unbuckle? couldn't you unbuckle? couldn't he unbuckle? couldn't we unbuckle? couldn't you unbuckle? couldn't they unbuckle?	couldn't I be unbuckling? couldn't you be unbuckling? couldn't he be unbuckling? couldn't we be unbuckling? couldn't you be unbuckling? couldn't they be unbuckling?
Perfect	V-ing perfect
couldn't I have unbuckled? couldn't you have unbuckled? couldn't he have unbuckled? couldn't we have unbuckled? couldn't you have unbuckled? couldn't they have unbuckled?	couldn't I have been unbuckling? couldn't you have been unbuckling? couldn't he have been unbuckling? couldn't we have been unbuckling? couldn't you have been unbuckling? couldn't they have been unbuckling?