I could diffuse you could diffuse he could diffuse we could diffuse you could diffuse they could diffuse
V-ing form
I could be diffusing you could be diffusing he could be diffusing we could be diffusing you could be diffusing they could be diffusing
Perfect
I could have diffused you could have diffused he could have diffused we could have diffused you could have diffused they could have diffused
V-ing perfect
I could have been diffusing you could have been diffusing he could have been diffusing we could have been diffusing you could have been diffusing they could have been diffusing
Negation
Simple form
I could not diffuse you could not diffuse he could not diffuse we could not diffuse you could not diffuse they could not diffuse
V-ing form
I could not be diffusing you could not be diffusing he could not be diffusing we could not be diffusing you could not be diffusing they could not be diffusing
Perfect
I could not have diffused you could not have diffused he could not have diffused we could not have diffused you could not have diffused they could not have diffused
V-ing perfect
I could not have been diffusing you could not have been diffusing he could not have been diffusing we could not have been diffusing you could not have been diffusing they could not have been diffusing
Interrogative form
Simple form
could I diffuse? could you diffuse? could he diffuse? could we diffuse? could you diffuse? could they diffuse?
V-ing form
could I be diffusing? could you be diffusing? could he be diffusing? could we be diffusing? could you be diffusing? could they be diffusing?
Perfect
could I have diffused? could you have diffused? could he have diffused? could we have diffused? could you have diffused? could they have diffused?
V-ing perfect
could I have been diffusing? could you have been diffusing? could he have been diffusing? could we have been diffusing? could you have been diffusing? could they have been diffusing?
Interro-negative form
Simple form
could I not diffuse? could you not diffuse? could he not diffuse? could we not diffuse? could you not diffuse? could they not diffuse?
V-ing form
could I not be diffusing? could you not be diffusing? could he not be diffusing? could we not be diffusing? could you not be diffusing? could they not be diffusing?
Perfect
could I not have diffused? could you not have diffused? could he not have diffused? could we not have diffused? could you not have diffused? could they not have diffused?
V-ing perfect
could I not have been diffusing? could you not have been diffusing? could he not have been diffusing? could we not have been diffusing? could you not have been diffusing? could they not have been diffusing?