English verb conjugation
CAN THREATEN

Regular verb: threaten - threatened - threatened

Affirmation

Simple form	V-ing form
I can threaten you can threaten he can threaten we can threaten you can threaten they can threaten	I can be threatening you can be threatening he can be threatening we can be threatening you can be threatening they can be threatening
Perfect	V-ing perfect
I can have threatened you can have threatened he can have threatened we can have threatened you can have threatened they can have threatened	I can have been threatening you can have been threatening he can have been threatening we can have been threatening you can have been threatening they can have been threatening

Negation

Simple form	V-ing form
I can't threaten you can't threaten he can't threaten we can't threaten you can't threaten they can't threaten	I can't be threatening you can't be threatening he can't be threatening we can't be threatening you can't be threatening they can't be threatening
Perfect	V-ing perfect
I can't have threatened you can't have threatened he can't have threatened we can't have threatened you can't have threatened they can't have threatened	I can't have been threatening you can't have been threatening he can't have been threatening we can't have been threatening you can't have been threatening they can't have been threatening

Interrogative form

Simple form	V-ing form
can I threaten? can you threaten? can he threaten? can we threaten? can you threaten? can they threaten?	can I be threatening? can you be threatening? can he be threatening? can we be threatening? can you be threatening? can they be threatening?
Perfect	V-ing perfect
can I have threatened? can you have threatened? can he have threatened? can we have threatened? can you have threatened? can they have threatened?	can I have been threatening? can you have been threatening? can he have been threatening? can we have been threatening? can you have been threatening? can they have been threatening?

Interro-negative form

Simple form	V-ing form
can't I threaten? can't you threaten? can't he threaten? can't we threaten? can't you threaten? can't they threaten?	can't I be threatening? can't you be threatening? can't he be threatening? can't we be threatening? can't you be threatening? can't they be threatening?
Perfect	V-ing perfect
can't I have threatened? can't you have threatened? can't he have threatened? can't we have threatened? can't you have threatened? can't they have threatened?	can't I have been threatening? can't you have been threatening? can't he have been threatening? can't we have been threatening? can't you have been threatening? can't they have been threatening?