I must enthuse you must enthuse he must enthuse we must enthuse you must enthuse they must enthuse
V-ing form
I must be enthusing you must be enthusing he must be enthusing we must be enthusing you must be enthusing they must be enthusing
Perfect
I must have enthused you must have enthused he must have enthused we must have enthused you must have enthused they must have enthused
V-ing perfect
I must have been enthusing you must have been enthusing he must have been enthusing we must have been enthusing you must have been enthusing they must have been enthusing
Negation
Simple form
I must not enthuse you must not enthuse he must not enthuse we must not enthuse you must not enthuse they must not enthuse
V-ing form
I must not be enthusing you must not be enthusing he must not be enthusing we must not be enthusing you must not be enthusing they must not be enthusing
Perfect
I must not have enthused you must not have enthused he must not have enthused we must not have enthused you must not have enthused they must not have enthused
V-ing perfect
I must not have been enthusing you must not have been enthusing he must not have been enthusing we must not have been enthusing you must not have been enthusing they must not have been enthusing
Interrogative form
Simple form
must I enthuse? must you enthuse? must he enthuse? must we enthuse? must you enthuse? must they enthuse?
V-ing form
must I be enthusing? must you be enthusing? must he be enthusing? must we be enthusing? must you be enthusing? must they be enthusing?
Perfect
must I have enthused? must you have enthused? must he have enthused? must we have enthused? must you have enthused? must they have enthused?
V-ing perfect
must I have been enthusing? must you have been enthusing? must he have been enthusing? must we have been enthusing? must you have been enthusing? must they have been enthusing?
Interro-negative form
Simple form
must I not enthuse? must you not enthuse? must he not enthuse? must we not enthuse? must you not enthuse? must they not enthuse?
V-ing form
must I not be enthusing? must you not be enthusing? must he not be enthusing? must we not be enthusing? must you not be enthusing? must they not be enthusing?
Perfect
must I not have enthused? must you not have enthused? must he not have enthused? must we not have enthused? must you not have enthused? must they not have enthused?
V-ing perfect
must I not have been enthusing? must you not have been enthusing? must he not have been enthusing? must we not have been enthusing? must you not have been enthusing? must they not have been enthusing?