English verb conjugation
COULD YOWL

Regular verb: yowl - yowled - yowled

Affirmation

Simple form	V-ing form
I could yowl you could yowl he could yowl we could yowl you could yowl they could yowl	I could be yowling you could be yowling he could be yowling we could be yowling you could be yowling they could be yowling
Perfect	V-ing perfect
I could have yowled you could have yowled he could have yowled we could have yowled you could have yowled they could have yowled	I could have been yowling you could have been yowling he could have been yowling we could have been yowling you could have been yowling they could have been yowling

Negation

Simple form	V-ing form
I couldn't yowl you couldn't yowl he couldn't yowl we couldn't yowl you couldn't yowl they couldn't yowl	I couldn't be yowling you couldn't be yowling he couldn't be yowling we couldn't be yowling you couldn't be yowling they couldn't be yowling
Perfect	V-ing perfect
I couldn't have yowled you couldn't have yowled he couldn't have yowled we couldn't have yowled you couldn't have yowled they couldn't have yowled	I couldn't have been yowling you couldn't have been yowling he couldn't have been yowling we couldn't have been yowling you couldn't have been yowling they couldn't have been yowling

Interrogative form

Simple form	V-ing form
could I yowl? could you yowl? could he yowl? could we yowl? could you yowl? could they yowl?	could I be yowling? could you be yowling? could he be yowling? could we be yowling? could you be yowling? could they be yowling?
Perfect	V-ing perfect
could I have yowled? could you have yowled? could he have yowled? could we have yowled? could you have yowled? could they have yowled?	could I have been yowling? could you have been yowling? could he have been yowling? could we have been yowling? could you have been yowling? could they have been yowling?

Interro-negative form

Simple form	V-ing form
couldn't I yowl? couldn't you yowl? couldn't he yowl? couldn't we yowl? couldn't you yowl? couldn't they yowl?	couldn't I be yowling? couldn't you be yowling? couldn't he be yowling? couldn't we be yowling? couldn't you be yowling? couldn't they be yowling?
Perfect	V-ing perfect
couldn't I have yowled? couldn't you have yowled? couldn't he have yowled? couldn't we have yowled? couldn't you have yowled? couldn't they have yowled?	couldn't I have been yowling? couldn't you have been yowling? couldn't he have been yowling? couldn't we have been yowling? couldn't you have been yowling? couldn't they have been yowling?