I must calve you must calve he must calve we must calve you must calve they must calve
V-ing form
I must be calving you must be calving he must be calving we must be calving you must be calving they must be calving
Perfect
I must have calved you must have calved he 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 he 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 he 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 he 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 he 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 he 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 he calve? must we calve? must you calve? must they calve?
V-ing form
must I be calving? must you be calving? must he be calving? must we be calving? must you be calving? must they be calving?
Perfect
must I have calved? must you have calved? must he 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 he 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 he 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 he 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 he 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 he not have been calving? must we not have been calving? must you not have been calving? must they not have been calving?