I could decode you could decode she could decode we could decode you could decode they could decode
V-ing form
I could be decoding you could be decoding she could be decoding we could be decoding you could be decoding they could be decoding
Perfect
I could have decoded you could have decoded she could have decoded we could have decoded you could have decoded they could have decoded
V-ing perfect
I could have been decoding you could have been decoding she could have been decoding we could have been decoding you could have been decoding they could have been decoding
Negation
Simple form
I could not decode you could not decode she could not decode we could not decode you could not decode they could not decode
V-ing form
I could not be decoding you could not be decoding she could not be decoding we could not be decoding you could not be decoding they could not be decoding
Perfect
I could not have decoded you could not have decoded she could not have decoded we could not have decoded you could not have decoded they could not have decoded
V-ing perfect
I could not have been decoding you could not have been decoding she could not have been decoding we could not have been decoding you could not have been decoding they could not have been decoding
Interrogative form
Simple form
could I decode? could you decode? could she decode? could we decode? could you decode? could they decode?
V-ing form
could I be decoding? could you be decoding? could she be decoding? could we be decoding? could you be decoding? could they be decoding?
Perfect
could I have decoded? could you have decoded? could she have decoded? could we have decoded? could you have decoded? could they have decoded?
V-ing perfect
could I have been decoding? could you have been decoding? could she have been decoding? could we have been decoding? could you have been decoding? could they have been decoding?
Interro-negative form
Simple form
could I not decode? could you not decode? could she not decode? could we not decode? could you not decode? could they not decode?
V-ing form
could I not be decoding? could you not be decoding? could she not be decoding? could we not be decoding? could you not be decoding? could they not be decoding?
Perfect
could I not have decoded? could you not have decoded? could she not have decoded? could we not have decoded? could you not have decoded? could they not have decoded?
V-ing perfect
could I not have been decoding? could you not have been decoding? could she not have been decoding? could we not have been decoding? could you not have been decoding? could they not have been decoding?