I could charge you could charge he could charge we could charge you could charge they could charge
V-ing form
I could be charging you could be charging he could be charging we could be charging you could be charging they could be charging
Perfect
I could have charged you could have charged he could have charged we could have charged you could have charged they could have charged
V-ing perfect
I could have been charging you could have been charging he could have been charging we could have been charging you could have been charging they could have been charging
Negation
Simple form
I could not charge you could not charge he could not charge we could not charge you could not charge they could not charge
V-ing form
I could not be charging you could not be charging he could not be charging we could not be charging you could not be charging they could not be charging
Perfect
I could not have charged you could not have charged he could not have charged we could not have charged you could not have charged they could not have charged
V-ing perfect
I could not have been charging you could not have been charging he could not have been charging we could not have been charging you could not have been charging they could not have been charging
Interrogative form
Simple form
could I charge? could you charge? could he charge? could we charge? could you charge? could they charge?
V-ing form
could I be charging? could you be charging? could he be charging? could we be charging? could you be charging? could they be charging?
Perfect
could I have charged? could you have charged? could he have charged? could we have charged? could you have charged? could they have charged?
V-ing perfect
could I have been charging? could you have been charging? could he have been charging? could we have been charging? could you have been charging? could they have been charging?
Interro-negative form
Simple form
could I not charge? could you not charge? could he not charge? could we not charge? could you not charge? could they not charge?
V-ing form
could I not be charging? could you not be charging? could he not be charging? could we not be charging? could you not be charging? could they not be charging?
Perfect
could I not have charged? could you not have charged? could he not have charged? could we not have charged? could you not have charged? could they not have charged?
V-ing perfect
could I not have been charging? could you not have been charging? could he not have been charging? could we not have been charging? could you not have been charging? could they not have been charging?