English verb conjugation
MUST SISE

Regular verb: sise - sised - sised

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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
I mustn't sise you mustn't sise he mustn't sise we mustn't sise you mustn't sise they mustn't sise	I mustn't be sising you mustn't be sising he mustn't be sising we mustn't be sising you mustn't be sising they mustn't be sising
Perfect	V-ing perfect
I mustn't have sised you mustn't have sised he mustn't have sised we mustn't have sised you mustn't have sised they mustn't have sised	I mustn't have been sising you mustn't have been sising he mustn't have been sising we mustn't have been sising you mustn't have been sising they mustn't have been sising

Interrogative form

Simple form	V-ing form
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?
Perfect	V-ing perfect
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
mustn't I sise? mustn't you sise? mustn't he sise? mustn't we sise? mustn't you sise? mustn't they sise?	mustn't I be sising? mustn't you be sising? mustn't he be sising? mustn't we be sising? mustn't you be sising? mustn't they be sising?
Perfect	V-ing perfect
mustn't I have sised? mustn't you have sised? mustn't he have sised? mustn't we have sised? mustn't you have sised? mustn't they have sised?	mustn't I have been sising? mustn't you have been sising? mustn't he have been sising? mustn't we have been sising? mustn't you have been sising? mustn't they have been sising?