must stratify
Regular verb: stratify - stratified- stratified

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must stratify
you must stratify
she must stratify
we must stratify
you must stratify
they must stratify 	I must be stratifying
you must be stratifying
she must be stratifying
we must be stratifying
you must be stratifying
they must be stratifying	I must have stratified
you must have stratified
she must have stratified
we must have stratified
you must have stratified
they must have stratified	I must have been stratifying
you must have been stratifying
she must have been stratifying
we must have been stratifying
you must have been stratifying
they must have been stratifying	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not stratify
you must not stratify
she must not stratify
we must not stratify
you must not stratify
they must not stratify 	I must not be stratifying
you must not be stratifying
she must not be stratifying
we must not be stratifying
you must not be stratifying
they must not be stratifying	I must not have stratified
you must not have stratified
she must not have stratified
we must not have stratified
you must not have stratified
they must not have stratified	I must not have been stratifying
you must not have been stratifying
she must not have been stratifying
we must not have been stratifying
you must not have been stratifying
they must not have been stratifying	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I stratify?
must you stratify?
must she stratify?
must we stratify?
must you stratify?
must they stratify? 	must I be stratifying?
must you be stratifying?
must she be stratifying?
must we be stratifying?
must you be stratifying?
must they be stratifying? 	must I have stratified?
must you have stratified?
must she have stratified?
must we have stratified?
must you have stratified?
must they have stratified? 	must I have been stratifying?
must you have been stratifying?
must she have been stratifying?
must we have been stratifying?
must you have been stratifying?
must they have been stratifying? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not stratify?
must you not stratify?
must she not stratify?
must we not stratify?
must you not stratify?
must they not stratify? 	must I not be stratifying?
must you not be stratifying?
must she not be stratifying?
must we not be stratifying?
must you not be stratifying?
must they not be stratifying? 	must I not have stratified?
must you not have stratified?
must she not have stratified?
must we not have stratified?
must you not have stratified?
must they not have stratified? 	must I not have been stratifying?
must you not have been stratifying?
must she not have been stratifying?
must we not have been stratifying?
must you not have been stratifying?
must they not have been stratifying?