English verb conjugation
COULD RATTLE

Regular verb: rattle - rattled - rattled

Affirmation

Simple form	V-ing form
I could rattle you could rattle he could rattle we could rattle you could rattle they could rattle	I could be rattling you could be rattling he could be rattling we could be rattling you could be rattling they could be rattling
Perfect	V-ing perfect
I could have rattled you could have rattled he could have rattled we could have rattled you could have rattled they could have rattled	I could have been rattling you could have been rattling he could have been rattling we could have been rattling you could have been rattling they could have been rattling

Negation

Simple form	V-ing form
I couldn't rattle you couldn't rattle he couldn't rattle we couldn't rattle you couldn't rattle they couldn't rattle	I couldn't be rattling you couldn't be rattling he couldn't be rattling we couldn't be rattling you couldn't be rattling they couldn't be rattling
Perfect	V-ing perfect
I couldn't have rattled you couldn't have rattled he couldn't have rattled we couldn't have rattled you couldn't have rattled they couldn't have rattled	I couldn't have been rattling you couldn't have been rattling he couldn't have been rattling we couldn't have been rattling you couldn't have been rattling they couldn't have been rattling

Interrogative form

Simple form	V-ing form
could I rattle? could you rattle? could he rattle? could we rattle? could you rattle? could they rattle?	could I be rattling? could you be rattling? could he be rattling? could we be rattling? could you be rattling? could they be rattling?
Perfect	V-ing perfect
could I have rattled? could you have rattled? could he have rattled? could we have rattled? could you have rattled? could they have rattled?	could I have been rattling? could you have been rattling? could he have been rattling? could we have been rattling? could you have been rattling? could they have been rattling?

Interro-negative form

Simple form	V-ing form
couldn't I rattle? couldn't you rattle? couldn't he rattle? couldn't we rattle? couldn't you rattle? couldn't they rattle?	couldn't I be rattling? couldn't you be rattling? couldn't he be rattling? couldn't we be rattling? couldn't you be rattling? couldn't they be rattling?
Perfect	V-ing perfect
couldn't I have rattled? couldn't you have rattled? couldn't he have rattled? couldn't we have rattled? couldn't you have rattled? couldn't they have rattled?	couldn't I have been rattling? couldn't you have been rattling? couldn't he have been rattling? couldn't we have been rattling? couldn't you have been rattling? couldn't they have been rattling?