must snowplough
Regular verb: snowplough - snowploughed- snowploughed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must snowplough
you must snowplough
he must snowplough
we must snowplough
you must snowplough
they must snowplough 	I must be snowploughing
you must be snowploughing
he must be snowploughing
we must be snowploughing
you must be snowploughing
they must be snowploughing	I must have snowploughed
you must have snowploughed
he must have snowploughed
we must have snowploughed
you must have snowploughed
they must have snowploughed	I must have been snowploughing
you must have been snowploughing
he must have been snowploughing
we must have been snowploughing
you must have been snowploughing
they must have been snowploughing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not snowplough
you must not snowplough
he must not snowplough
we must not snowplough
you must not snowplough
they must not snowplough 	I must not be snowploughing
you must not be snowploughing
he must not be snowploughing
we must not be snowploughing
you must not be snowploughing
they must not be snowploughing	I must not have snowploughed
you must not have snowploughed
he must not have snowploughed
we must not have snowploughed
you must not have snowploughed
they must not have snowploughed	I must not have been snowploughing
you must not have been snowploughing
he must not have been snowploughing
we must not have been snowploughing
you must not have been snowploughing
they must not have been snowploughing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I snowplough?
must you snowplough?
must he snowplough?
must we snowplough?
must you snowplough?
must they snowplough? 	must I be snowploughing?
must you be snowploughing?
must he be snowploughing?
must we be snowploughing?
must you be snowploughing?
must they be snowploughing? 	must I have snowploughed?
must you have snowploughed?
must he have snowploughed?
must we have snowploughed?
must you have snowploughed?
must they have snowploughed? 	must I have been snowploughing?
must you have been snowploughing?
must he have been snowploughing?
must we have been snowploughing?
must you have been snowploughing?
must they have been snowploughing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not snowplough?
must you not snowplough?
must he not snowplough?
must we not snowplough?
must you not snowplough?
must they not snowplough? 	must I not be snowploughing?
must you not be snowploughing?
must he not be snowploughing?
must we not be snowploughing?
must you not be snowploughing?
must they not be snowploughing? 	must I not have snowploughed?
must you not have snowploughed?
must he not have snowploughed?
must we not have snowploughed?
must you not have snowploughed?
must they not have snowploughed? 	must I not have been snowploughing?
must you not have been snowploughing?
must he not have been snowploughing?
must we not have been snowploughing?
must you not have been snowploughing?
must they not have been snowploughing?