I could infect you could infect she could infect we could infect you could infect they could infect
V-ing form
I could be infecting you could be infecting she could be infecting we could be infecting you could be infecting they could be infecting
Perfect
I could have infected you could have infected she could have infected we could have infected you could have infected they could have infected
V-ing perfect
I could have been infecting you could have been infecting she could have been infecting we could have been infecting you could have been infecting they could have been infecting
Negation
Simple form
I could not infect you could not infect she could not infect we could not infect you could not infect they could not infect
V-ing form
I could not be infecting you could not be infecting she could not be infecting we could not be infecting you could not be infecting they could not be infecting
Perfect
I could not have infected you could not have infected she could not have infected we could not have infected you could not have infected they could not have infected
V-ing perfect
I could not have been infecting you could not have been infecting she could not have been infecting we could not have been infecting you could not have been infecting they could not have been infecting
Interrogative form
Simple form
could I infect? could you infect? could she infect? could we infect? could you infect? could they infect?
V-ing form
could I be infecting? could you be infecting? could she be infecting? could we be infecting? could you be infecting? could they be infecting?
Perfect
could I have infected? could you have infected? could she have infected? could we have infected? could you have infected? could they have infected?
V-ing perfect
could I have been infecting? could you have been infecting? could she have been infecting? could we have been infecting? could you have been infecting? could they have been infecting?
Interro-negative form
Simple form
could I not infect? could you not infect? could she not infect? could we not infect? could you not infect? could they not infect?
V-ing form
could I not be infecting? could you not be infecting? could she not be infecting? could we not be infecting? could you not be infecting? could they not be infecting?
Perfect
could I not have infected? could you not have infected? could she not have infected? could we not have infected? could you not have infected? could they not have infected?
V-ing perfect
could I not have been infecting? could you not have been infecting? could she not have been infecting? could we not have been infecting? could you not have been infecting? could they not have been infecting?