English verb conjugation
MUST SIGHTSEE

Regular verb: sightsee - sightseed - sightseed

Affirmation

Simple form	V-ing form
I must sightsee you must sightsee she must sightsee we must sightsee you must sightsee they must sightsee	I must be sightseeing you must be sightseeing she must be sightseeing we must be sightseeing you must be sightseeing they must be sightseeing
Perfect	V-ing perfect
I must have sightseed you must have sightseed she must have sightseed we must have sightseed you must have sightseed they must have sightseed	I must have been sightseeing you must have been sightseeing she must have been sightseeing we must have been sightseeing you must have been sightseeing they must have been sightseeing

Negation

Simple form	V-ing form
I mustn't sightsee you mustn't sightsee she mustn't sightsee we mustn't sightsee you mustn't sightsee they mustn't sightsee	I mustn't be sightseeing you mustn't be sightseeing she mustn't be sightseeing we mustn't be sightseeing you mustn't be sightseeing they mustn't be sightseeing
Perfect	V-ing perfect
I mustn't have sightseed you mustn't have sightseed she mustn't have sightseed we mustn't have sightseed you mustn't have sightseed they mustn't have sightseed	I mustn't have been sightseeing you mustn't have been sightseeing she mustn't have been sightseeing we mustn't have been sightseeing you mustn't have been sightseeing they mustn't have been sightseeing

Interrogative form

Simple form	V-ing form
must I sightsee? must you sightsee? must she sightsee? must we sightsee? must you sightsee? must they sightsee?	must I be sightseeing? must you be sightseeing? must she be sightseeing? must we be sightseeing? must you be sightseeing? must they be sightseeing?
Perfect	V-ing perfect
must I have sightseed? must you have sightseed? must she have sightseed? must we have sightseed? must you have sightseed? must they have sightseed?	must I have been sightseeing? must you have been sightseeing? must she have been sightseeing? must we have been sightseeing? must you have been sightseeing? must they have been sightseeing?

Interro-negative form

Simple form	V-ing form
mustn't I sightsee? mustn't you sightsee? mustn't she sightsee? mustn't we sightsee? mustn't you sightsee? mustn't they sightsee?	mustn't I be sightseeing? mustn't you be sightseeing? mustn't she be sightseeing? mustn't we be sightseeing? mustn't you be sightseeing? mustn't they be sightseeing?
Perfect	V-ing perfect
mustn't I have sightseed? mustn't you have sightseed? mustn't she have sightseed? mustn't we have sightseed? mustn't you have sightseed? mustn't they have sightseed?	mustn't I have been sightseeing? mustn't you have been sightseeing? mustn't she have been sightseeing? mustn't we have been sightseeing? mustn't you have been sightseeing? mustn't they have been sightseeing?