English verb conjugation
COULD SHIFT

Regular verb: shift - shifted - shifted

Affirmation

Simple form	V-ing form
I could shift you could shift he could shift we could shift you could shift they could shift	I could be shifting you could be shifting he could be shifting we could be shifting you could be shifting they could be shifting
Perfect	V-ing perfect
I could have shifted you could have shifted he could have shifted we could have shifted you could have shifted they could have shifted	I could have been shifting you could have been shifting he could have been shifting we could have been shifting you could have been shifting they could have been shifting

Negation

Simple form	V-ing form
I couldn't shift you couldn't shift he couldn't shift we couldn't shift you couldn't shift they couldn't shift	I couldn't be shifting you couldn't be shifting he couldn't be shifting we couldn't be shifting you couldn't be shifting they couldn't be shifting
Perfect	V-ing perfect
I couldn't have shifted you couldn't have shifted he couldn't have shifted we couldn't have shifted you couldn't have shifted they couldn't have shifted	I couldn't have been shifting you couldn't have been shifting he couldn't have been shifting we couldn't have been shifting you couldn't have been shifting they couldn't have been shifting

Interrogative form

Simple form	V-ing form
could I shift? could you shift? could he shift? could we shift? could you shift? could they shift?	could I be shifting? could you be shifting? could he be shifting? could we be shifting? could you be shifting? could they be shifting?
Perfect	V-ing perfect
could I have shifted? could you have shifted? could he have shifted? could we have shifted? could you have shifted? could they have shifted?	could I have been shifting? could you have been shifting? could he have been shifting? could we have been shifting? could you have been shifting? could they have been shifting?

Interro-negative form

Simple form	V-ing form
couldn't I shift? couldn't you shift? couldn't he shift? couldn't we shift? couldn't you shift? couldn't they shift?	couldn't I be shifting? couldn't you be shifting? couldn't he be shifting? couldn't we be shifting? couldn't you be shifting? couldn't they be shifting?
Perfect	V-ing perfect
couldn't I have shifted? couldn't you have shifted? couldn't he have shifted? couldn't we have shifted? couldn't you have shifted? couldn't they have shifted?	couldn't I have been shifting? couldn't you have been shifting? couldn't he have been shifting? couldn't we have been shifting? couldn't you have been shifting? couldn't they have been shifting?