English verb conjugation
COULD CUBE

Regular verb: cube - cubed - cubed

Affirmation

Simple form	V-ing form
I could cube you could cube she could cube we could cube you could cube they could cube	I could be cubing you could be cubing she could be cubing we could be cubing you could be cubing they could be cubing
Perfect	V-ing perfect
I could have cubed you could have cubed she could have cubed we could have cubed you could have cubed they could have cubed	I could have been cubing you could have been cubing she could have been cubing we could have been cubing you could have been cubing they could have been cubing

Negation

Simple form	V-ing form
I couldn't cube you couldn't cube she couldn't cube we couldn't cube you couldn't cube they couldn't cube	I couldn't be cubing you couldn't be cubing she couldn't be cubing we couldn't be cubing you couldn't be cubing they couldn't be cubing
Perfect	V-ing perfect
I couldn't have cubed you couldn't have cubed she couldn't have cubed we couldn't have cubed you couldn't have cubed they couldn't have cubed	I couldn't have been cubing you couldn't have been cubing she couldn't have been cubing we couldn't have been cubing you couldn't have been cubing they couldn't have been cubing

Interrogative form

Simple form	V-ing form
could I cube? could you cube? could she cube? could we cube? could you cube? could they cube?	could I be cubing? could you be cubing? could she be cubing? could we be cubing? could you be cubing? could they be cubing?
Perfect	V-ing perfect
could I have cubed? could you have cubed? could she have cubed? could we have cubed? could you have cubed? could they have cubed?	could I have been cubing? could you have been cubing? could she have been cubing? could we have been cubing? could you have been cubing? could they have been cubing?

Interro-negative form

Simple form	V-ing form
couldn't I cube? couldn't you cube? couldn't she cube? couldn't we cube? couldn't you cube? couldn't they cube?	couldn't I be cubing? couldn't you be cubing? couldn't she be cubing? couldn't we be cubing? couldn't you be cubing? couldn't they be cubing?
Perfect	V-ing perfect
couldn't I have cubed? couldn't you have cubed? couldn't she have cubed? couldn't we have cubed? couldn't you have cubed? couldn't they have cubed?	couldn't I have been cubing? couldn't you have been cubing? couldn't she have been cubing? couldn't we have been cubing? couldn't you have been cubing? couldn't they have been cubing?