I could unfold you could unfold he could unfold we could unfold you could unfold they could unfold
V-ing form
I could be unfolding you could be unfolding he could be unfolding we could be unfolding you could be unfolding they could be unfolding
Perfect
I could have unfolded you could have unfolded he could have unfolded we could have unfolded you could have unfolded they could have unfolded
V-ing perfect
I could have been unfolding you could have been unfolding he could have been unfolding we could have been unfolding you could have been unfolding they could have been unfolding
Negation
Simple form
I couldn't unfold you couldn't unfold he couldn't unfold we couldn't unfold you couldn't unfold they couldn't unfold
V-ing form
I couldn't be unfolding you couldn't be unfolding he couldn't be unfolding we couldn't be unfolding you couldn't be unfolding they couldn't be unfolding
Perfect
I couldn't have unfolded you couldn't have unfolded he couldn't have unfolded we couldn't have unfolded you couldn't have unfolded they couldn't have unfolded
V-ing perfect
I couldn't have been unfolding you couldn't have been unfolding he couldn't have been unfolding we couldn't have been unfolding you couldn't have been unfolding they couldn't have been unfolding
Interrogative form
Simple form
could I unfold? could you unfold? could he unfold? could we unfold? could you unfold? could they unfold?
V-ing form
could I be unfolding? could you be unfolding? could he be unfolding? could we be unfolding? could you be unfolding? could they be unfolding?
Perfect
could I have unfolded? could you have unfolded? could he have unfolded? could we have unfolded? could you have unfolded? could they have unfolded?
V-ing perfect
could I have been unfolding? could you have been unfolding? could he have been unfolding? could we have been unfolding? could you have been unfolding? could they have been unfolding?
Interro-negative form
Simple form
couldn't I unfold? couldn't you unfold? couldn't he unfold? couldn't we unfold? couldn't you unfold? couldn't they unfold?
V-ing form
couldn't I be unfolding? couldn't you be unfolding? couldn't he be unfolding? couldn't we be unfolding? couldn't you be unfolding? couldn't they be unfolding?
Perfect
couldn't I have unfolded? couldn't you have unfolded? couldn't he have unfolded? couldn't we have unfolded? couldn't you have unfolded? couldn't they have unfolded?
V-ing perfect
couldn't I have been unfolding? couldn't you have been unfolding? couldn't he have been unfolding? couldn't we have been unfolding? couldn't you have been unfolding? couldn't they have been unfolding?