I can threaten you can threaten she can threaten we can threaten you can threaten they can threaten
V-ing form
I can be threatening you can be threatening she can be threatening we can be threatening you can be threatening they can be threatening
Perfect
I can have threatened you can have threatened she can have threatened we can have threatened you can have threatened they can have threatened
V-ing perfect
I can have been threatening you can have been threatening she can have been threatening we can have been threatening you can have been threatening they can have been threatening
Negation
Simple form
I cannot threaten you cannot threaten she cannot threaten we cannot threaten you cannot threaten they cannot threaten
V-ing form
I cannot be threatening you cannot be threatening she cannot be threatening we cannot be threatening you cannot be threatening they cannot be threatening
Perfect
I cannot have threatened you cannot have threatened she cannot have threatened we cannot have threatened you cannot have threatened they cannot have threatened
V-ing perfect
I cannot have been threatening you cannot have been threatening she cannot have been threatening we cannot have been threatening you cannot have been threatening they cannot have been threatening
Interrogative form
Simple form
can I threaten? can you threaten? can she threaten? can we threaten? can you threaten? can they threaten?
V-ing form
can I be threatening? can you be threatening? can she be threatening? can we be threatening? can you be threatening? can they be threatening?
Perfect
can I have threatened? can you have threatened? can she have threatened? can we have threatened? can you have threatened? can they have threatened?
V-ing perfect
can I have been threatening? can you have been threatening? can she have been threatening? can we have been threatening? can you have been threatening? can they have been threatening?
Interro-negative form
Simple form
can I not threaten? can you not threaten? can she not threaten? can we not threaten? can you not threaten? can they not threaten?
V-ing form
can I not be threatening? can you not be threatening? can she not be threatening? can we not be threatening? can you not be threatening? can they not be threatening?
Perfect
can I not have threatened? can you not have threatened? can she not have threatened? can we not have threatened? can you not have threatened? can they not have threatened?
V-ing perfect
can I not have been threatening? can you not have been threatening? can she not have been threatening? can we not have been threatening? can you not have been threatening? can they not have been threatening?