
Regular verb: threaten - threatened - threatened
Simple form | V-ing form | 
| I could threaten you could threaten he could threaten we could threaten you could threaten they could threaten  | 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 | V-ing 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  | 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  | 
Simple form | V-ing 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  | 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 | V-ing 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  | 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  | 
Simple form | V-ing form | 
| could I threaten? could you threaten? could he threaten? could we threaten? could you threaten? could they threaten?  | 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 | V-ing 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?  | 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?  | 
Simple form | V-ing 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?  | 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 | V-ing 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?  | 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?  |