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