must sise
Regular verb: sise - sised- sised

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must sise
you must sise
he must sise
we must sise
you must sise
they must sise 	I must be sising
you must be sising
he must be sising
we must be sising
you must be sising
they must be sising	I must have sised
you must have sised
he must have sised
we must have sised
you must have sised
they must have sised	I must have been sising
you must have been sising
he must have been sising
we must have been sising
you must have been sising
they must have been sising	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not sise
you must not sise
he must not sise
we must not sise
you must not sise
they must not sise 	I must not be sising
you must not be sising
he must not be sising
we must not be sising
you must not be sising
they must not be sising	I must not have sised
you must not have sised
he must not have sised
we must not have sised
you must not have sised
they must not have sised	I must not have been sising
you must not have been sising
he must not have been sising
we must not have been sising
you must not have been sising
they must not have been sising	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I sise?
must you sise?
must he sise?
must we sise?
must you sise?
must they sise? 	must I be sising?
must you be sising?
must he be sising?
must we be sising?
must you be sising?
must they be sising? 	must I have sised?
must you have sised?
must he have sised?
must we have sised?
must you have sised?
must they have sised? 	must I have been sising?
must you have been sising?
must he have been sising?
must we have been sising?
must you have been sising?
must they have been sising? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not sise?
must you not sise?
must he not sise?
must we not sise?
must you not sise?
must they not sise? 	must I not be sising?
must you not be sising?
must he not be sising?
must we not be sising?
must you not be sising?
must they not be sising? 	must I not have sised?
must you not have sised?
must he not have sised?
must we not have sised?
must you not have sised?
must they not have sised? 	must I not have been sising?
must you not have been sising?
must he not have been sising?
must we not have been sising?
must you not have been sising?
must they not have been sising?