must leaven
Regular verb: leaven - leavened- leavened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must leaven
you must leaven
he must leaven
we must leaven
you must leaven
they must leaven 	I must be leavening
you must be leavening
he must be leavening
we must be leavening
you must be leavening
they must be leavening	I must have leavened
you must have leavened
he must have leavened
we must have leavened
you must have leavened
they must have leavened	I must have been leavening
you must have been leavening
he must have been leavening
we must have been leavening
you must have been leavening
they must have been leavening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not leaven
you must not leaven
he must not leaven
we must not leaven
you must not leaven
they must not leaven 	I must not be leavening
you must not be leavening
he must not be leavening
we must not be leavening
you must not be leavening
they must not be leavening	I must not have leavened
you must not have leavened
he must not have leavened
we must not have leavened
you must not have leavened
they must not have leavened	I must not have been leavening
you must not have been leavening
he must not have been leavening
we must not have been leavening
you must not have been leavening
they must not have been leavening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I leaven?
must you leaven?
must he leaven?
must we leaven?
must you leaven?
must they leaven? 	must I be leavening?
must you be leavening?
must he be leavening?
must we be leavening?
must you be leavening?
must they be leavening? 	must I have leavened?
must you have leavened?
must he have leavened?
must we have leavened?
must you have leavened?
must they have leavened? 	must I have been leavening?
must you have been leavening?
must he have been leavening?
must we have been leavening?
must you have been leavening?
must they have been leavening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not leaven?
must you not leaven?
must he not leaven?
must we not leaven?
must you not leaven?
must they not leaven? 	must I not be leavening?
must you not be leavening?
must he not be leavening?
must we not be leavening?
must you not be leavening?
must they not be leavening? 	must I not have leavened?
must you not have leavened?
must he not have leavened?
must we not have leavened?
must you not have leavened?
must they not have leavened? 	must I not have been leavening?
must you not have been leavening?
must he not have been leavening?
must we not have been leavening?
must you not have been leavening?
must they not have been leavening?