I could code you could code he could code we could code you could code they could code
V-ing form
I could be coding you could be coding he could be coding we could be coding you could be coding they could be coding
Perfect
I could have coded you could have coded he could have coded we could have coded you could have coded they could have coded
V-ing perfect
I could have been coding you could have been coding he could have been coding we could have been coding you could have been coding they could have been coding
Negation
Simple form
I could not code you could not code he could not code we could not code you could not code they could not code
V-ing form
I could not be coding you could not be coding he could not be coding we could not be coding you could not be coding they could not be coding
Perfect
I could not have coded you could not have coded he could not have coded we could not have coded you could not have coded they could not have coded
V-ing perfect
I could not have been coding you could not have been coding he could not have been coding we could not have been coding you could not have been coding they could not have been coding
Interrogative form
Simple form
could I code? could you code? could he code? could we code? could you code? could they code?
V-ing form
could I be coding? could you be coding? could he be coding? could we be coding? could you be coding? could they be coding?
Perfect
could I have coded? could you have coded? could he have coded? could we have coded? could you have coded? could they have coded?
V-ing perfect
could I have been coding? could you have been coding? could he have been coding? could we have been coding? could you have been coding? could they have been coding?
Interro-negative form
Simple form
could I not code? could you not code? could he not code? could we not code? could you not code? could they not code?
V-ing form
could I not be coding? could you not be coding? could he not be coding? could we not be coding? could you not be coding? could they not be coding?
Perfect
could I not have coded? could you not have coded? could he not have coded? could we not have coded? could you not have coded? could they not have coded?
V-ing perfect
could I not have been coding? could you not have been coding? could he not have been coding? could we not have been coding? could you not have been coding? could they not have been coding?