I could gobble you could gobble she could gobble we could gobble you could gobble they could gobble
V-ing form
I could be gobbling you could be gobbling she could be gobbling we could be gobbling you could be gobbling they could be gobbling
Perfect
I could have gobbled you could have gobbled she could have gobbled we could have gobbled you could have gobbled they could have gobbled
V-ing perfect
I could have been gobbling you could have been gobbling she could have been gobbling we could have been gobbling you could have been gobbling they could have been gobbling
Negation
Simple form
I couldn't gobble you couldn't gobble she couldn't gobble we couldn't gobble you couldn't gobble they couldn't gobble
V-ing form
I couldn't be gobbling you couldn't be gobbling she couldn't be gobbling we couldn't be gobbling you couldn't be gobbling they couldn't be gobbling
Perfect
I couldn't have gobbled you couldn't have gobbled she couldn't have gobbled we couldn't have gobbled you couldn't have gobbled they couldn't have gobbled
V-ing perfect
I couldn't have been gobbling you couldn't have been gobbling she couldn't have been gobbling we couldn't have been gobbling you couldn't have been gobbling they couldn't have been gobbling
Interrogative form
Simple form
could I gobble? could you gobble? could she gobble? could we gobble? could you gobble? could they gobble?
V-ing form
could I be gobbling? could you be gobbling? could she be gobbling? could we be gobbling? could you be gobbling? could they be gobbling?
Perfect
could I have gobbled? could you have gobbled? could she have gobbled? could we have gobbled? could you have gobbled? could they have gobbled?
V-ing perfect
could I have been gobbling? could you have been gobbling? could she have been gobbling? could we have been gobbling? could you have been gobbling? could they have been gobbling?
Interro-negative form
Simple form
couldn't I gobble? couldn't you gobble? couldn't she gobble? couldn't we gobble? couldn't you gobble? couldn't they gobble?
V-ing form
couldn't I be gobbling? couldn't you be gobbling? couldn't she be gobbling? couldn't we be gobbling? couldn't you be gobbling? couldn't they be gobbling?
Perfect
couldn't I have gobbled? couldn't you have gobbled? couldn't she have gobbled? couldn't we have gobbled? couldn't you have gobbled? couldn't they have gobbled?
V-ing perfect
couldn't I have been gobbling? couldn't you have been gobbling? couldn't she have been gobbling? couldn't we have been gobbling? couldn't you have been gobbling? couldn't they have been gobbling?