I could glower you could glower he could glower we could glower you could glower they could glower
V-ing form
I could be glowering you could be glowering he could be glowering we could be glowering you could be glowering they could be glowering
Perfect
I could have glowered you could have glowered he could have glowered we could have glowered you could have glowered they could have glowered
V-ing perfect
I could have been glowering you could have been glowering he could have been glowering we could have been glowering you could have been glowering they could have been glowering
Negation
Simple form
I could not glower you could not glower he could not glower we could not glower you could not glower they could not glower
V-ing form
I could not be glowering you could not be glowering he could not be glowering we could not be glowering you could not be glowering they could not be glowering
Perfect
I could not have glowered you could not have glowered he could not have glowered we could not have glowered you could not have glowered they could not have glowered
V-ing perfect
I could not have been glowering you could not have been glowering he could not have been glowering we could not have been glowering you could not have been glowering they could not have been glowering
Interrogative form
Simple form
could I glower? could you glower? could he glower? could we glower? could you glower? could they glower?
V-ing form
could I be glowering? could you be glowering? could he be glowering? could we be glowering? could you be glowering? could they be glowering?
Perfect
could I have glowered? could you have glowered? could he have glowered? could we have glowered? could you have glowered? could they have glowered?
V-ing perfect
could I have been glowering? could you have been glowering? could he have been glowering? could we have been glowering? could you have been glowering? could they have been glowering?
Interro-negative form
Simple form
could I not glower? could you not glower? could he not glower? could we not glower? could you not glower? could they not glower?
V-ing form
could I not be glowering? could you not be glowering? could he not be glowering? could we not be glowering? could you not be glowering? could they not be glowering?
Perfect
could I not have glowered? could you not have glowered? could he not have glowered? could we not have glowered? could you not have glowered? could they not have glowered?
V-ing perfect
could I not have been glowering? could you not have been glowering? could he not have been glowering? could we not have been glowering? could you not have been glowering? could they not have been glowering?