English verb conjugation
COULD EXPAND

Regular verb: expand - expanded - expanded

Affirmation

Simple form	V-ing form
I could expand you could expand he could expand we could expand you could expand they could expand	I could be expanding you could be expanding he could be expanding we could be expanding you could be expanding they could be expanding
Perfect	V-ing perfect
I could have expanded you could have expanded he could have expanded we could have expanded you could have expanded they could have expanded	I could have been expanding you could have been expanding he could have been expanding we could have been expanding you could have been expanding they could have been expanding

Negation

Simple form	V-ing form
I couldn't expand you couldn't expand he couldn't expand we couldn't expand you couldn't expand they couldn't expand	I couldn't be expanding you couldn't be expanding he couldn't be expanding we couldn't be expanding you couldn't be expanding they couldn't be expanding
Perfect	V-ing perfect
I couldn't have expanded you couldn't have expanded he couldn't have expanded we couldn't have expanded you couldn't have expanded they couldn't have expanded	I couldn't have been expanding you couldn't have been expanding he couldn't have been expanding we couldn't have been expanding you couldn't have been expanding they couldn't have been expanding

Interrogative form

Simple form	V-ing form
could I expand? could you expand? could he expand? could we expand? could you expand? could they expand?	could I be expanding? could you be expanding? could he be expanding? could we be expanding? could you be expanding? could they be expanding?
Perfect	V-ing perfect
could I have expanded? could you have expanded? could he have expanded? could we have expanded? could you have expanded? could they have expanded?	could I have been expanding? could you have been expanding? could he have been expanding? could we have been expanding? could you have been expanding? could they have been expanding?

Interro-negative form

Simple form	V-ing form
couldn't I expand? couldn't you expand? couldn't he expand? couldn't we expand? couldn't you expand? couldn't they expand?	couldn't I be expanding? couldn't you be expanding? couldn't he be expanding? couldn't we be expanding? couldn't you be expanding? couldn't they be expanding?
Perfect	V-ing perfect
couldn't I have expanded? couldn't you have expanded? couldn't he have expanded? couldn't we have expanded? couldn't you have expanded? couldn't they have expanded?	couldn't I have been expanding? couldn't you have been expanding? couldn't he have been expanding? couldn't we have been expanding? couldn't you have been expanding? couldn't they have been expanding?