I could pipette you could pipette he could pipette we could pipette you could pipette they could pipette
V-ing form
I could be pipetting you could be pipetting he could be pipetting we could be pipetting you could be pipetting they could be pipetting
Perfect
I could have pipetted you could have pipetted he could have pipetted we could have pipetted you could have pipetted they could have pipetted
V-ing perfect
I could have been pipetting you could have been pipetting he could have been pipetting we could have been pipetting you could have been pipetting they could have been pipetting
Negation
Simple form
I could not pipette you could not pipette he could not pipette we could not pipette you could not pipette they could not pipette
V-ing form
I could not be pipetting you could not be pipetting he could not be pipetting we could not be pipetting you could not be pipetting they could not be pipetting
Perfect
I could not have pipetted you could not have pipetted he could not have pipetted we could not have pipetted you could not have pipetted they could not have pipetted
V-ing perfect
I could not have been pipetting you could not have been pipetting he could not have been pipetting we could not have been pipetting you could not have been pipetting they could not have been pipetting
Interrogative form
Simple form
could I pipette? could you pipette? could he pipette? could we pipette? could you pipette? could they pipette?
V-ing form
could I be pipetting? could you be pipetting? could he be pipetting? could we be pipetting? could you be pipetting? could they be pipetting?
Perfect
could I have pipetted? could you have pipetted? could he have pipetted? could we have pipetted? could you have pipetted? could they have pipetted?
V-ing perfect
could I have been pipetting? could you have been pipetting? could he have been pipetting? could we have been pipetting? could you have been pipetting? could they have been pipetting?
Interro-negative form
Simple form
could I not pipette? could you not pipette? could he not pipette? could we not pipette? could you not pipette? could they not pipette?
V-ing form
could I not be pipetting? could you not be pipetting? could he not be pipetting? could we not be pipetting? could you not be pipetting? could they not be pipetting?
Perfect
could I not have pipetted? could you not have pipetted? could he not have pipetted? could we not have pipetted? could you not have pipetted? could they not have pipetted?
V-ing perfect
could I not have been pipetting? could you not have been pipetting? could he not have been pipetting? could we not have been pipetting? could you not have been pipetting? could they not have been pipetting?