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