English verb conjugation
MUST SIP

Regular verb: sip - sipped - sipped

Affirmation

Simple form	V-ing form
I must sip you must sip she must sip we must sip you must sip they must sip	I must be sipping you must be sipping she 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 she 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 she 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 she 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 she 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 she 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 she 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 she sip? must we sip? must you sip? must they sip?	must I be sipping? must you be sipping? must she 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 she 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 she 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 she 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 she 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 she 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 she have been sipping? mustn't we have been sipping? mustn't you have been sipping? mustn't they have been sipping?