English verb conjugation
MUST SIP

Regular verb: sip - sipped - sipped

Affirmation

Simple form	V-ing form
I must sip you must sip he must sip we must sip you must sip they must sip	I must be sipping you must be sipping he must be sipping we must be sipping you must be sipping they must be sipping
Perfect	V-ing perfect
I must have sipped you must have sipped he must have sipped we must have sipped you must have sipped they must have sipped	I must have been sipping you must have been sipping he must have been sipping we must have been sipping you must have been sipping they must have been sipping

Negation

Simple form	V-ing form
I mustn't sip you mustn't sip he mustn't sip we mustn't sip you mustn't sip they mustn't sip	I mustn't be sipping you mustn't be sipping he mustn't be sipping we mustn't be sipping you mustn't be sipping they mustn't be sipping
Perfect	V-ing perfect
I mustn't have sipped you mustn't have sipped he mustn't have sipped we mustn't have sipped you mustn't have sipped they mustn't have sipped	I mustn't have been sipping you mustn't have been sipping he mustn't have been sipping we mustn't have been sipping you mustn't have been sipping they mustn't have been sipping

Interrogative form

Simple form	V-ing form
must I sip? must you sip? must he sip? must we sip? must you sip? must they sip?	must I be sipping? must you be sipping? must he be sipping? must we be sipping? must you be sipping? must they be sipping?
Perfect	V-ing perfect
must I have sipped? must you have sipped? must he have sipped? must we have sipped? must you have sipped? must they have sipped?	must I have been sipping? must you have been sipping? must he have been sipping? must we have been sipping? must you have been sipping? must they have been sipping?

Interro-negative form

Simple form	V-ing form
mustn't I sip? mustn't you sip? mustn't he sip? mustn't we sip? mustn't you sip? mustn't they sip?	mustn't I be sipping? mustn't you be sipping? mustn't he be sipping? mustn't we be sipping? mustn't you be sipping? mustn't they be sipping?
Perfect	V-ing perfect
mustn't I have sipped? mustn't you have sipped? mustn't he have sipped? mustn't we have sipped? mustn't you have sipped? mustn't they have sipped?	mustn't I have been sipping? mustn't you have been sipping? mustn't he have been sipping? mustn't we have been sipping? mustn't you have been sipping? mustn't they have been sipping?