I can authenticate you can authenticate she can authenticate we can authenticate you can authenticate they can authenticate
V-ing form
I can be authenticating you can be authenticating she can be authenticating we can be authenticating you can be authenticating they can be authenticating
Perfect
I can have authenticated you can have authenticated she can have authenticated we can have authenticated you can have authenticated they can have authenticated
V-ing perfect
I can have been authenticating you can have been authenticating she can have been authenticating we can have been authenticating you can have been authenticating they can have been authenticating
Negation
Simple form
I cannot authenticate you cannot authenticate she cannot authenticate we cannot authenticate you cannot authenticate they cannot authenticate
V-ing form
I cannot be authenticating you cannot be authenticating she cannot be authenticating we cannot be authenticating you cannot be authenticating they cannot be authenticating
Perfect
I cannot have authenticated you cannot have authenticated she cannot have authenticated we cannot have authenticated you cannot have authenticated they cannot have authenticated
V-ing perfect
I cannot have been authenticating you cannot have been authenticating she cannot have been authenticating we cannot have been authenticating you cannot have been authenticating they cannot have been authenticating
Interrogative form
Simple form
can I authenticate? can you authenticate? can she authenticate? can we authenticate? can you authenticate? can they authenticate?
V-ing form
can I be authenticating? can you be authenticating? can she be authenticating? can we be authenticating? can you be authenticating? can they be authenticating?
Perfect
can I have authenticated? can you have authenticated? can she have authenticated? can we have authenticated? can you have authenticated? can they have authenticated?
V-ing perfect
can I have been authenticating? can you have been authenticating? can she have been authenticating? can we have been authenticating? can you have been authenticating? can they have been authenticating?
Interro-negative form
Simple form
can I not authenticate? can you not authenticate? can she not authenticate? can we not authenticate? can you not authenticate? can they not authenticate?
V-ing form
can I not be authenticating? can you not be authenticating? can she not be authenticating? can we not be authenticating? can you not be authenticating? can they not be authenticating?
Perfect
can I not have authenticated? can you not have authenticated? can she not have authenticated? can we not have authenticated? can you not have authenticated? can they not have authenticated?
V-ing perfect
can I not have been authenticating? can you not have been authenticating? can she not have been authenticating? can we not have been authenticating? can you not have been authenticating? can they not have been authenticating?