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 couldn't charge you couldn't charge he couldn't charge we couldn't charge you couldn't charge they couldn't charge
V-ing form
I couldn't be charging you couldn't be charging he couldn't be charging we couldn't be charging you couldn't be charging they couldn't be charging
Perfect
I couldn't have charged you couldn't have charged he couldn't have charged we couldn't have charged you couldn't have charged they couldn't have charged
V-ing perfect
I couldn't have been charging you couldn't have been charging he couldn't have been charging we couldn't have been charging you couldn't have been charging they couldn't 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
couldn't I charge? couldn't you charge? couldn't he charge? couldn't we charge? couldn't you charge? couldn't they charge?
V-ing form
couldn't I be charging? couldn't you be charging? couldn't he be charging? couldn't we be charging? couldn't you be charging? couldn't they be charging?
Perfect
couldn't I have charged? couldn't you have charged? couldn't he have charged? couldn't we have charged? couldn't you have charged? couldn't they have charged?
V-ing perfect
couldn't I have been charging? couldn't you have been charging? couldn't he have been charging? couldn't we have been charging? couldn't you have been charging? couldn't they have been charging?