must lack
Verbo regolare: lack - lacked- lacked

Affermazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I must lack
you must lack
he must lack
we must lack
you must lack
they must lack 	I must be lacking
you must be lacking
he must be lacking
we must be lacking
you must be lacking
they must be lacking	I must have lacked
you must have lacked
he must have lacked
we must have lacked
you must have lacked
they must have lacked	I must have been lacking
you must have been lacking
he must have been lacking
we must have been lacking
you must have been lacking
they must have been lacking	

Negazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I mustn't lack
you mustn't lack
he mustn't lack
we mustn't lack
you mustn't lack
they mustn't lack 	I mustn't be lacking
you mustn't be lacking
he mustn't be lacking
we mustn't be lacking
you mustn't be lacking
they mustn't be lacking	I mustn't have lacked
you mustn't have lacked
he mustn't have lacked
we mustn't have lacked
you mustn't have lacked
they mustn't have lacked	I mustn't have been lacking
you mustn't have been lacking
he mustn't have been lacking
we mustn't have been lacking
you mustn't have been lacking
they mustn't have been lacking	

Forma interrogativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
must I lack?
must you lack?
must he lack?
must we lack?
must you lack?
must they lack? 	must I be lacking?
must you be lacking?
must he be lacking?
must we be lacking?
must you be lacking?
must they be lacking? 	must I have lacked?
must you have lacked?
must he have lacked?
must we have lacked?
must you have lacked?
must they have lacked? 	must I have been lacking?
must you have been lacking?
must he have been lacking?
must we have been lacking?
must you have been lacking?
must they have been lacking? 	

Forma interro-negativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
mustn't I lack?
mustn't you lack?
mustn't he lack?
mustn't we lack?
mustn't you lack?
mustn't they lack? 	mustn't I be lacking?
mustn't you be lacking?
mustn't he be lacking?
mustn't we be lacking?
mustn't you be lacking?
mustn't they be lacking? 	mustn't I have lacked?
mustn't you have lacked?
mustn't he have lacked?
mustn't we have lacked?
mustn't you have lacked?
mustn't they have lacked? 	mustn't I have been lacking?
mustn't you have been lacking?
mustn't he have been lacking?
mustn't we have been lacking?
mustn't you have been lacking?
mustn't they have been lacking?