must ossify
Regular verb: ossify - ossified- ossified

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must ossify
you must ossify
she must ossify
we must ossify
you must ossify
they must ossify 	I must be ossifying
you must be ossifying
she must be ossifying
we must be ossifying
you must be ossifying
they must be ossifying	I must have ossified
you must have ossified
she must have ossified
we must have ossified
you must have ossified
they must have ossified	I must have been ossifying
you must have been ossifying
she must have been ossifying
we must have been ossifying
you must have been ossifying
they must have been ossifying	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't ossify
you mustn't ossify
she mustn't ossify
we mustn't ossify
you mustn't ossify
they mustn't ossify 	I mustn't be ossifying
you mustn't be ossifying
she mustn't be ossifying
we mustn't be ossifying
you mustn't be ossifying
they mustn't be ossifying	I mustn't have ossified
you mustn't have ossified
she mustn't have ossified
we mustn't have ossified
you mustn't have ossified
they mustn't have ossified	I mustn't have been ossifying
you mustn't have been ossifying
she mustn't have been ossifying
we mustn't have been ossifying
you mustn't have been ossifying
they mustn't have been ossifying	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I ossify?
must you ossify?
must she ossify?
must we ossify?
must you ossify?
must they ossify? 	must I be ossifying?
must you be ossifying?
must she be ossifying?
must we be ossifying?
must you be ossifying?
must they be ossifying? 	must I have ossified?
must you have ossified?
must she have ossified?
must we have ossified?
must you have ossified?
must they have ossified? 	must I have been ossifying?
must you have been ossifying?
must she have been ossifying?
must we have been ossifying?
must you have been ossifying?
must they have been ossifying? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I ossify?
mustn't you ossify?
mustn't she ossify?
mustn't we ossify?
mustn't you ossify?
mustn't they ossify? 	mustn't I be ossifying?
mustn't you be ossifying?
mustn't she be ossifying?
mustn't we be ossifying?
mustn't you be ossifying?
mustn't they be ossifying? 	mustn't I have ossified?
mustn't you have ossified?
mustn't she have ossified?
mustn't we have ossified?
mustn't you have ossified?
mustn't they have ossified? 	mustn't I have been ossifying?
mustn't you have been ossifying?
mustn't she have been ossifying?
mustn't we have been ossifying?
mustn't you have been ossifying?
mustn't they have been ossifying?