English verb conjugation
COULD GROWL

Regular verb: growl - growled - growled

Affirmation

Simple form	V-ing form
I could growl you could growl he could growl we could growl you could growl they could growl	I could be growling you could be growling he could be growling we could be growling you could be growling they could be growling
Perfect	V-ing perfect
I could have growled you could have growled he could have growled we could have growled you could have growled they could have growled	I could have been growling you could have been growling he could have been growling we could have been growling you could have been growling they could have been growling

Negation

Simple form	V-ing form
I couldn't growl you couldn't growl he couldn't growl we couldn't growl you couldn't growl they couldn't growl	I couldn't be growling you couldn't be growling he couldn't be growling we couldn't be growling you couldn't be growling they couldn't be growling
Perfect	V-ing perfect
I couldn't have growled you couldn't have growled he couldn't have growled we couldn't have growled you couldn't have growled they couldn't have growled	I couldn't have been growling you couldn't have been growling he couldn't have been growling we couldn't have been growling you couldn't have been growling they couldn't have been growling

Interrogative form

Simple form	V-ing form
could I growl? could you growl? could he growl? could we growl? could you growl? could they growl?	could I be growling? could you be growling? could he be growling? could we be growling? could you be growling? could they be growling?
Perfect	V-ing perfect
could I have growled? could you have growled? could he have growled? could we have growled? could you have growled? could they have growled?	could I have been growling? could you have been growling? could he have been growling? could we have been growling? could you have been growling? could they have been growling?

Interro-negative form

Simple form	V-ing form
couldn't I growl? couldn't you growl? couldn't he growl? couldn't we growl? couldn't you growl? couldn't they growl?	couldn't I be growling? couldn't you be growling? couldn't he be growling? couldn't we be growling? couldn't you be growling? couldn't they be growling?
Perfect	V-ing perfect
couldn't I have growled? couldn't you have growled? couldn't he have growled? couldn't we have growled? couldn't you have growled? couldn't they have growled?	couldn't I have been growling? couldn't you have been growling? couldn't he have been growling? couldn't we have been growling? couldn't you have been growling? couldn't they have been growling?