English verb conjugation
MUST DESCEND

Regular verb: descend - descended - descended

Affirmation

Simple form	V-ing form
I must descend you must descend he must descend we must descend you must descend they must descend	I must be descending you must be descending he must be descending we must be descending you must be descending they must be descending
Perfect	V-ing perfect
I must have descended you must have descended he must have descended we must have descended you must have descended they must have descended	I must have been descending you must have been descending he must have been descending we must have been descending you must have been descending they must have been descending

Negation

Simple form	V-ing form
I mustn't descend you mustn't descend he mustn't descend we mustn't descend you mustn't descend they mustn't descend	I mustn't be descending you mustn't be descending he mustn't be descending we mustn't be descending you mustn't be descending they mustn't be descending
Perfect	V-ing perfect
I mustn't have descended you mustn't have descended he mustn't have descended we mustn't have descended you mustn't have descended they mustn't have descended	I mustn't have been descending you mustn't have been descending he mustn't have been descending we mustn't have been descending you mustn't have been descending they mustn't have been descending

Interrogative form

Simple form	V-ing form
must I descend? must you descend? must he descend? must we descend? must you descend? must they descend?	must I be descending? must you be descending? must he be descending? must we be descending? must you be descending? must they be descending?
Perfect	V-ing perfect
must I have descended? must you have descended? must he have descended? must we have descended? must you have descended? must they have descended?	must I have been descending? must you have been descending? must he have been descending? must we have been descending? must you have been descending? must they have been descending?

Interro-negative form

Simple form	V-ing form
mustn't I descend? mustn't you descend? mustn't he descend? mustn't we descend? mustn't you descend? mustn't they descend?	mustn't I be descending? mustn't you be descending? mustn't he be descending? mustn't we be descending? mustn't you be descending? mustn't they be descending?
Perfect	V-ing perfect
mustn't I have descended? mustn't you have descended? mustn't he have descended? mustn't we have descended? mustn't you have descended? mustn't they have descended?	mustn't I have been descending? mustn't you have been descending? mustn't he have been descending? mustn't we have been descending? mustn't you have been descending? mustn't they have been descending?