I could relapse you could relapse he could relapse we could relapse you could relapse they could relapse
V-ing form
I could be relapsing you could be relapsing he could be relapsing we could be relapsing you could be relapsing they could be relapsing
Perfect
I could have relapsed you could have relapsed he could have relapsed we could have relapsed you could have relapsed they could have relapsed
V-ing perfect
I could have been relapsing you could have been relapsing he could have been relapsing we could have been relapsing you could have been relapsing they could have been relapsing
Negation
Simple form
I could not relapse you could not relapse he could not relapse we could not relapse you could not relapse they could not relapse
V-ing form
I could not be relapsing you could not be relapsing he could not be relapsing we could not be relapsing you could not be relapsing they could not be relapsing
Perfect
I could not have relapsed you could not have relapsed he could not have relapsed we could not have relapsed you could not have relapsed they could not have relapsed
V-ing perfect
I could not have been relapsing you could not have been relapsing he could not have been relapsing we could not have been relapsing you could not have been relapsing they could not have been relapsing
Interrogative form
Simple form
could I relapse? could you relapse? could he relapse? could we relapse? could you relapse? could they relapse?
V-ing form
could I be relapsing? could you be relapsing? could he be relapsing? could we be relapsing? could you be relapsing? could they be relapsing?
Perfect
could I have relapsed? could you have relapsed? could he have relapsed? could we have relapsed? could you have relapsed? could they have relapsed?
V-ing perfect
could I have been relapsing? could you have been relapsing? could he have been relapsing? could we have been relapsing? could you have been relapsing? could they have been relapsing?
Interro-negative form
Simple form
could I not relapse? could you not relapse? could he not relapse? could we not relapse? could you not relapse? could they not relapse?
V-ing form
could I not be relapsing? could you not be relapsing? could he not be relapsing? could we not be relapsing? could you not be relapsing? could they not be relapsing?
Perfect
could I not have relapsed? could you not have relapsed? could he not have relapsed? could we not have relapsed? could you not have relapsed? could they not have relapsed?
V-ing perfect
could I not have been relapsing? could you not have been relapsing? could he not have been relapsing? could we not have been relapsing? could you not have been relapsing? could they not have been relapsing?