I could quote you could quote he could quote we could quote you could quote they could quote
V-ing form
I could be quoting you could be quoting he could be quoting we could be quoting you could be quoting they could be quoting
Perfect
I could have quoted you could have quoted he could have quoted we could have quoted you could have quoted they could have quoted
V-ing perfect
I could have been quoting you could have been quoting he could have been quoting we could have been quoting you could have been quoting they could have been quoting
Negation
Simple form
I could not quote you could not quote he could not quote we could not quote you could not quote they could not quote
V-ing form
I could not be quoting you could not be quoting he could not be quoting we could not be quoting you could not be quoting they could not be quoting
Perfect
I could not have quoted you could not have quoted he could not have quoted we could not have quoted you could not have quoted they could not have quoted
V-ing perfect
I could not have been quoting you could not have been quoting he could not have been quoting we could not have been quoting you could not have been quoting they could not have been quoting
Interrogative form
Simple form
could I quote? could you quote? could he quote? could we quote? could you quote? could they quote?
V-ing form
could I be quoting? could you be quoting? could he be quoting? could we be quoting? could you be quoting? could they be quoting?
Perfect
could I have quoted? could you have quoted? could he have quoted? could we have quoted? could you have quoted? could they have quoted?
V-ing perfect
could I have been quoting? could you have been quoting? could he have been quoting? could we have been quoting? could you have been quoting? could they have been quoting?
Interro-negative form
Simple form
could I not quote? could you not quote? could he not quote? could we not quote? could you not quote? could they not quote?
V-ing form
could I not be quoting? could you not be quoting? could he not be quoting? could we not be quoting? could you not be quoting? could they not be quoting?
Perfect
could I not have quoted? could you not have quoted? could he not have quoted? could we not have quoted? could you not have quoted? could they not have quoted?
V-ing perfect
could I not have been quoting? could you not have been quoting? could he not have been quoting? could we not have been quoting? could you not have been quoting? could they not have been quoting?