I must avail you must avail he must avail we must avail you must avail they must avail
V-ing form
I must be availing you must be availing he must be availing we must be availing you must be availing they must be availing
Perfect
I must have availed you must have availed he must have availed we must have availed you must have availed they must have availed
V-ing perfect
I must have been availing you must have been availing he must have been availing we must have been availing you must have been availing they must have been availing
Negation
Simple form
I must not avail you must not avail he must not avail we must not avail you must not avail they must not avail
V-ing form
I must not be availing you must not be availing he must not be availing we must not be availing you must not be availing they must not be availing
Perfect
I must not have availed you must not have availed he must not have availed we must not have availed you must not have availed they must not have availed
V-ing perfect
I must not have been availing you must not have been availing he must not have been availing we must not have been availing you must not have been availing they must not have been availing
Interrogative form
Simple form
must I avail? must you avail? must he avail? must we avail? must you avail? must they avail?
V-ing form
must I be availing? must you be availing? must he be availing? must we be availing? must you be availing? must they be availing?
Perfect
must I have availed? must you have availed? must he have availed? must we have availed? must you have availed? must they have availed?
V-ing perfect
must I have been availing? must you have been availing? must he have been availing? must we have been availing? must you have been availing? must they have been availing?
Interro-negative form
Simple form
must I not avail? must you not avail? must he not avail? must we not avail? must you not avail? must they not avail?
V-ing form
must I not be availing? must you not be availing? must he not be availing? must we not be availing? must you not be availing? must they not be availing?
Perfect
must I not have availed? must you not have availed? must he not have availed? must we not have availed? must you not have availed? must they not have availed?
V-ing perfect
must I not have been availing? must you not have been availing? must he not have been availing? must we not have been availing? must you not have been availing? must they not have been availing?