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 mustn't avail you mustn't avail he mustn't avail we mustn't avail you mustn't avail they mustn't avail
V-ing form
I mustn't be availing you mustn't be availing he mustn't be availing we mustn't be availing you mustn't be availing they mustn't be availing
Perfect
I mustn't have availed you mustn't have availed he mustn't have availed we mustn't have availed you mustn't have availed they mustn't have availed
V-ing perfect
I mustn't have been availing you mustn't have been availing he mustn't have been availing we mustn't have been availing you mustn't have been availing they mustn't 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
mustn't I avail? mustn't you avail? mustn't he avail? mustn't we avail? mustn't you avail? mustn't they avail?
V-ing form
mustn't I be availing? mustn't you be availing? mustn't he be availing? mustn't we be availing? mustn't you be availing? mustn't they be availing?
Perfect
mustn't I have availed? mustn't you have availed? mustn't he have availed? mustn't we have availed? mustn't you have availed? mustn't they have availed?
V-ing perfect
mustn't I have been availing? mustn't you have been availing? mustn't he have been availing? mustn't we have been availing? mustn't you have been availing? mustn't they have been availing?