English verb conjugation
MUST CROON

Regular verb: croon - crooned - crooned

Affirmation

Simple form	V-ing form
I must croon you must croon he must croon we must croon you must croon they must croon	I must be crooning you must be crooning he must be crooning we must be crooning you must be crooning they must be crooning
Perfect	V-ing perfect
I must have crooned you must have crooned he must have crooned we must have crooned you must have crooned they must have crooned	I must have been crooning you must have been crooning he must have been crooning we must have been crooning you must have been crooning they must have been crooning

Negation

Simple form	V-ing form
I must not croon you must not croon he must not croon we must not croon you must not croon they must not croon	I must not be crooning you must not be crooning he must not be crooning we must not be crooning you must not be crooning they must not be crooning
Perfect	V-ing perfect
I must not have crooned you must not have crooned he must not have crooned we must not have crooned you must not have crooned they must not have crooned	I must not have been crooning you must not have been crooning he must not have been crooning we must not have been crooning you must not have been crooning they must not have been crooning

Interrogative form

Simple form	V-ing form
must I croon? must you croon? must he croon? must we croon? must you croon? must they croon?	must I be crooning? must you be crooning? must he be crooning? must we be crooning? must you be crooning? must they be crooning?
Perfect	V-ing perfect
must I have crooned? must you have crooned? must he have crooned? must we have crooned? must you have crooned? must they have crooned?	must I have been crooning? must you have been crooning? must he have been crooning? must we have been crooning? must you have been crooning? must they have been crooning?

Interro-negative form

Simple form	V-ing form
must I not croon? must you not croon? must he not croon? must we not croon? must you not croon? must they not croon?	must I not be crooning? must you not be crooning? must he not be crooning? must we not be crooning? must you not be crooning? must they not be crooning?
Perfect	V-ing perfect
must I not have crooned? must you not have crooned? must he not have crooned? must we not have crooned? must you not have crooned? must they not have crooned?	must I not have been crooning? must you not have been crooning? must he not have been crooning? must we not have been crooning? must you not have been crooning? must they not have been crooning?