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