English verb conjugation
CAN ERR

Regular verb: err - erred - erred

Affirmation

Simple form	V-ing form
I can err you can err she can err we can err you can err they can err	I can be erring you can be erring she can be erring we can be erring you can be erring they can be erring
Perfect	V-ing perfect
I can have erred you can have erred she can have erred we can have erred you can have erred they can have erred	I can have been erring you can have been erring she can have been erring we can have been erring you can have been erring they can have been erring

Negation

Simple form	V-ing form
I cannot err you cannot err she cannot err we cannot err you cannot err they cannot err	I cannot be erring you cannot be erring she cannot be erring we cannot be erring you cannot be erring they cannot be erring
Perfect	V-ing perfect
I cannot have erred you cannot have erred she cannot have erred we cannot have erred you cannot have erred they cannot have erred	I cannot have been erring you cannot have been erring she cannot have been erring we cannot have been erring you cannot have been erring they cannot have been erring

Interrogative form

Simple form	V-ing form
can I err? can you err? can she err? can we err? can you err? can they err?	can I be erring? can you be erring? can she be erring? can we be erring? can you be erring? can they be erring?
Perfect	V-ing perfect
can I have erred? can you have erred? can she have erred? can we have erred? can you have erred? can they have erred?	can I have been erring? can you have been erring? can she have been erring? can we have been erring? can you have been erring? can they have been erring?

Interro-negative form

Simple form	V-ing form
can I not err? can you not err? can she not err? can we not err? can you not err? can they not err?	can I not be erring? can you not be erring? can she not be erring? can we not be erring? can you not be erring? can they not be erring?
Perfect	V-ing perfect
can I not have erred? can you not have erred? can she not have erred? can we not have erred? can you not have erred? can they not have erred?	can I not have been erring? can you not have been erring? can she not have been erring? can we not have been erring? can you not have been erring? can they not have been erring?