English verb conjugation
CAN CRACK

Regular verb: crack - cracked - cracked

Affirmation

Simple form	V-ing form
I can crack you can crack he can crack we can crack you can crack they can crack	I can be cracking you can be cracking he can be cracking we can be cracking you can be cracking they can be cracking
Perfect	V-ing perfect
I can have cracked you can have cracked he can have cracked we can have cracked you can have cracked they can have cracked	I can have been cracking you can have been cracking he can have been cracking we can have been cracking you can have been cracking they can have been cracking

Negation

Simple form	V-ing form
I cannot crack you cannot crack he cannot crack we cannot crack you cannot crack they cannot crack	I cannot be cracking you cannot be cracking he cannot be cracking we cannot be cracking you cannot be cracking they cannot be cracking
Perfect	V-ing perfect
I cannot have cracked you cannot have cracked he cannot have cracked we cannot have cracked you cannot have cracked they cannot have cracked	I cannot have been cracking you cannot have been cracking he cannot have been cracking we cannot have been cracking you cannot have been cracking they cannot have been cracking

Interrogative form

Simple form	V-ing form
can I crack? can you crack? can he crack? can we crack? can you crack? can they crack?	can I be cracking? can you be cracking? can he be cracking? can we be cracking? can you be cracking? can they be cracking?
Perfect	V-ing perfect
can I have cracked? can you have cracked? can he have cracked? can we have cracked? can you have cracked? can they have cracked?	can I have been cracking? can you have been cracking? can he have been cracking? can we have been cracking? can you have been cracking? can they have been cracking?

Interro-negative form

Simple form	V-ing form
can I not crack? can you not crack? can he not crack? can we not crack? can you not crack? can they not crack?	can I not be cracking? can you not be cracking? can he not be cracking? can we not be cracking? can you not be cracking? can they not be cracking?
Perfect	V-ing perfect
can I not have cracked? can you not have cracked? can he not have cracked? can we not have cracked? can you not have cracked? can they not have cracked?	can I not have been cracking? can you not have been cracking? can he not have been cracking? can we not have been cracking? can you not have been cracking? can they not have been cracking?