I could adhere you could adhere he could adhere we could adhere you could adhere they could adhere
V-ing form
I could be adhering you could be adhering he could be adhering we could be adhering you could be adhering they could be adhering
Perfect
I could have adhered you could have adhered he could have adhered we could have adhered you could have adhered they could have adhered
V-ing perfect
I could have been adhering you could have been adhering he could have been adhering we could have been adhering you could have been adhering they could have been adhering
Negation
Simple form
I couldn't adhere you couldn't adhere he couldn't adhere we couldn't adhere you couldn't adhere they couldn't adhere
V-ing form
I couldn't be adhering you couldn't be adhering he couldn't be adhering we couldn't be adhering you couldn't be adhering they couldn't be adhering
Perfect
I couldn't have adhered you couldn't have adhered he couldn't have adhered we couldn't have adhered you couldn't have adhered they couldn't have adhered
V-ing perfect
I couldn't have been adhering you couldn't have been adhering he couldn't have been adhering we couldn't have been adhering you couldn't have been adhering they couldn't have been adhering
Interrogative form
Simple form
could I adhere? could you adhere? could he adhere? could we adhere? could you adhere? could they adhere?
V-ing form
could I be adhering? could you be adhering? could he be adhering? could we be adhering? could you be adhering? could they be adhering?
Perfect
could I have adhered? could you have adhered? could he have adhered? could we have adhered? could you have adhered? could they have adhered?
V-ing perfect
could I have been adhering? could you have been adhering? could he have been adhering? could we have been adhering? could you have been adhering? could they have been adhering?
Interro-negative form
Simple form
couldn't I adhere? couldn't you adhere? couldn't he adhere? couldn't we adhere? couldn't you adhere? couldn't they adhere?
V-ing form
couldn't I be adhering? couldn't you be adhering? couldn't he be adhering? couldn't we be adhering? couldn't you be adhering? couldn't they be adhering?
Perfect
couldn't I have adhered? couldn't you have adhered? couldn't he have adhered? couldn't we have adhered? couldn't you have adhered? couldn't they have adhered?
V-ing perfect
couldn't I have been adhering? couldn't you have been adhering? couldn't he have been adhering? couldn't we have been adhering? couldn't you have been adhering? couldn't they have been adhering?