must excavate
Regular verb: excavate - excavated- excavated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must excavate
you must excavate
he must excavate
we must excavate
you must excavate
they must excavate 	I must be excavating
you must be excavating
he must be excavating
we must be excavating
you must be excavating
they must be excavating	I must have excavated
you must have excavated
he must have excavated
we must have excavated
you must have excavated
they must have excavated	I must have been excavating
you must have been excavating
he must have been excavating
we must have been excavating
you must have been excavating
they must have been excavating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't excavate
you mustn't excavate
he mustn't excavate
we mustn't excavate
you mustn't excavate
they mustn't excavate 	I mustn't be excavating
you mustn't be excavating
he mustn't be excavating
we mustn't be excavating
you mustn't be excavating
they mustn't be excavating	I mustn't have excavated
you mustn't have excavated
he mustn't have excavated
we mustn't have excavated
you mustn't have excavated
they mustn't have excavated	I mustn't have been excavating
you mustn't have been excavating
he mustn't have been excavating
we mustn't have been excavating
you mustn't have been excavating
they mustn't have been excavating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I excavate?
must you excavate?
must he excavate?
must we excavate?
must you excavate?
must they excavate? 	must I be excavating?
must you be excavating?
must he be excavating?
must we be excavating?
must you be excavating?
must they be excavating? 	must I have excavated?
must you have excavated?
must he have excavated?
must we have excavated?
must you have excavated?
must they have excavated? 	must I have been excavating?
must you have been excavating?
must he have been excavating?
must we have been excavating?
must you have been excavating?
must they have been excavating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I excavate?
mustn't you excavate?
mustn't he excavate?
mustn't we excavate?
mustn't you excavate?
mustn't they excavate? 	mustn't I be excavating?
mustn't you be excavating?
mustn't he be excavating?
mustn't we be excavating?
mustn't you be excavating?
mustn't they be excavating? 	mustn't I have excavated?
mustn't you have excavated?
mustn't he have excavated?
mustn't we have excavated?
mustn't you have excavated?
mustn't they have excavated? 	mustn't I have been excavating?
mustn't you have been excavating?
mustn't he have been excavating?
mustn't we have been excavating?
mustn't you have been excavating?
mustn't they have been excavating?