I could tom you could tom he could tom we could tom you could tom they could tom
V-ing form
I could be toming you could be toming he could be toming we could be toming you could be toming they could be toming
Perfect
I could have tomed you could have tomed he could have tomed we could have tomed you could have tomed they could have tomed
V-ing perfect
I could have been toming you could have been toming he could have been toming we could have been toming you could have been toming they could have been toming
Negation
Simple form
I could not tom you could not tom he could not tom we could not tom you could not tom they could not tom
V-ing form
I could not be toming you could not be toming he could not be toming we could not be toming you could not be toming they could not be toming
Perfect
I could not have tomed you could not have tomed he could not have tomed we could not have tomed you could not have tomed they could not have tomed
V-ing perfect
I could not have been toming you could not have been toming he could not have been toming we could not have been toming you could not have been toming they could not have been toming
Interrogative form
Simple form
could I tom? could you tom? could he tom? could we tom? could you tom? could they tom?
V-ing form
could I be toming? could you be toming? could he be toming? could we be toming? could you be toming? could they be toming?
Perfect
could I have tomed? could you have tomed? could he have tomed? could we have tomed? could you have tomed? could they have tomed?
V-ing perfect
could I have been toming? could you have been toming? could he have been toming? could we have been toming? could you have been toming? could they have been toming?
Interro-negative form
Simple form
could I not tom? could you not tom? could he not tom? could we not tom? could you not tom? could they not tom?
V-ing form
could I not be toming? could you not be toming? could he not be toming? could we not be toming? could you not be toming? could they not be toming?
Perfect
could I not have tomed? could you not have tomed? could he not have tomed? could we not have tomed? could you not have tomed? could they not have tomed?
V-ing perfect
could I not have been toming? could you not have been toming? could he not have been toming? could we not have been toming? could you not have been toming? could they not have been toming?