I could advise you could advise he could advise we could advise you could advise they could advise
V-ing form
I could be advising you could be advising he could be advising we could be advising you could be advising they could be advising
Perfect
I could have advised you could have advised he could have advised we could have advised you could have advised they could have advised
V-ing perfect
I could have been advising you could have been advising he could have been advising we could have been advising you could have been advising they could have been advising
Negation
Simple form
I could not advise you could not advise he could not advise we could not advise you could not advise they could not advise
V-ing form
I could not be advising you could not be advising he could not be advising we could not be advising you could not be advising they could not be advising
Perfect
I could not have advised you could not have advised he could not have advised we could not have advised you could not have advised they could not have advised
V-ing perfect
I could not have been advising you could not have been advising he could not have been advising we could not have been advising you could not have been advising they could not have been advising
Interrogative form
Simple form
could I advise? could you advise? could he advise? could we advise? could you advise? could they advise?
V-ing form
could I be advising? could you be advising? could he be advising? could we be advising? could you be advising? could they be advising?
Perfect
could I have advised? could you have advised? could he have advised? could we have advised? could you have advised? could they have advised?
V-ing perfect
could I have been advising? could you have been advising? could he have been advising? could we have been advising? could you have been advising? could they have been advising?
Interro-negative form
Simple form
could I not advise? could you not advise? could he not advise? could we not advise? could you not advise? could they not advise?
V-ing form
could I not be advising? could you not be advising? could he not be advising? could we not be advising? could you not be advising? could they not be advising?
Perfect
could I not have advised? could you not have advised? could he not have advised? could we not have advised? could you not have advised? could they not have advised?
V-ing perfect
could I not have been advising? could you not have been advising? could he not have been advising? could we not have been advising? could you not have been advising? could they not have been advising?