I must calve you must calve she must calve we must calve you must calve they must calve
V-ing form
I must be calving you must be calving she must be calving we must be calving you must be calving they must be calving
Perfect
I must have calved you must have calved she must have calved we must have calved you must have calved they must have calved
V-ing perfect
I must have been calving you must have been calving she must have been calving we must have been calving you must have been calving they must have been calving
Negation
Simple form
I must not calve you must not calve she must not calve we must not calve you must not calve they must not calve
V-ing form
I must not be calving you must not be calving she must not be calving we must not be calving you must not be calving they must not be calving
Perfect
I must not have calved you must not have calved she must not have calved we must not have calved you must not have calved they must not have calved
V-ing perfect
I must not have been calving you must not have been calving she must not have been calving we must not have been calving you must not have been calving they must not have been calving
Interrogative form
Simple form
must I calve? must you calve? must she calve? must we calve? must you calve? must they calve?
V-ing form
must I be calving? must you be calving? must she be calving? must we be calving? must you be calving? must they be calving?
Perfect
must I have calved? must you have calved? must she have calved? must we have calved? must you have calved? must they have calved?
V-ing perfect
must I have been calving? must you have been calving? must she have been calving? must we have been calving? must you have been calving? must they have been calving?
Interro-negative form
Simple form
must I not calve? must you not calve? must she not calve? must we not calve? must you not calve? must they not calve?
V-ing form
must I not be calving? must you not be calving? must she not be calving? must we not be calving? must you not be calving? must they not be calving?
Perfect
must I not have calved? must you not have calved? must she not have calved? must we not have calved? must you not have calved? must they not have calved?
V-ing perfect
must I not have been calving? must you not have been calving? must she not have been calving? must we not have been calving? must you not have been calving? must they not have been calving?