must shield
Regular verb: shield - shielded- shielded

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must shield
you must shield
he must shield
we must shield
you must shield
they must shield 	I must be shielding
you must be shielding
he must be shielding
we must be shielding
you must be shielding
they must be shielding	I must have shielded
you must have shielded
he must have shielded
we must have shielded
you must have shielded
they must have shielded	I must have been shielding
you must have been shielding
he must have been shielding
we must have been shielding
you must have been shielding
they must have been shielding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not shield
you must not shield
he must not shield
we must not shield
you must not shield
they must not shield 	I must not be shielding
you must not be shielding
he must not be shielding
we must not be shielding
you must not be shielding
they must not be shielding	I must not have shielded
you must not have shielded
he must not have shielded
we must not have shielded
you must not have shielded
they must not have shielded	I must not have been shielding
you must not have been shielding
he must not have been shielding
we must not have been shielding
you must not have been shielding
they must not have been shielding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I shield?
must you shield?
must he shield?
must we shield?
must you shield?
must they shield? 	must I be shielding?
must you be shielding?
must he be shielding?
must we be shielding?
must you be shielding?
must they be shielding? 	must I have shielded?
must you have shielded?
must he have shielded?
must we have shielded?
must you have shielded?
must they have shielded? 	must I have been shielding?
must you have been shielding?
must he have been shielding?
must we have been shielding?
must you have been shielding?
must they have been shielding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not shield?
must you not shield?
must he not shield?
must we not shield?
must you not shield?
must they not shield? 	must I not be shielding?
must you not be shielding?
must he not be shielding?
must we not be shielding?
must you not be shielding?
must they not be shielding? 	must I not have shielded?
must you not have shielded?
must he not have shielded?
must we not have shielded?
must you not have shielded?
must they not have shielded? 	must I not have been shielding?
must you not have been shielding?
must he not have been shielding?
must we not have been shielding?
must you not have been shielding?
must they not have been shielding?