I must engender you must engender he must engender we must engender you must engender they must engender
V-ing form
I must be engendering you must be engendering he must be engendering we must be engendering you must be engendering they must be engendering
Perfect
I must have engendered you must have engendered he must have engendered we must have engendered you must have engendered they must have engendered
V-ing perfect
I must have been engendering you must have been engendering he must have been engendering we must have been engendering you must have been engendering they must have been engendering
Negation
Simple form
I mustn't engender you mustn't engender he mustn't engender we mustn't engender you mustn't engender they mustn't engender
V-ing form
I mustn't be engendering you mustn't be engendering he mustn't be engendering we mustn't be engendering you mustn't be engendering they mustn't be engendering
Perfect
I mustn't have engendered you mustn't have engendered he mustn't have engendered we mustn't have engendered you mustn't have engendered they mustn't have engendered
V-ing perfect
I mustn't have been engendering you mustn't have been engendering he mustn't have been engendering we mustn't have been engendering you mustn't have been engendering they mustn't have been engendering
Interrogative form
Simple form
must I engender? must you engender? must he engender? must we engender? must you engender? must they engender?
V-ing form
must I be engendering? must you be engendering? must he be engendering? must we be engendering? must you be engendering? must they be engendering?
Perfect
must I have engendered? must you have engendered? must he have engendered? must we have engendered? must you have engendered? must they have engendered?
V-ing perfect
must I have been engendering? must you have been engendering? must he have been engendering? must we have been engendering? must you have been engendering? must they have been engendering?
Interro-negative form
Simple form
mustn't I engender? mustn't you engender? mustn't he engender? mustn't we engender? mustn't you engender? mustn't they engender?
V-ing form
mustn't I be engendering? mustn't you be engendering? mustn't he be engendering? mustn't we be engendering? mustn't you be engendering? mustn't they be engendering?
Perfect
mustn't I have engendered? mustn't you have engendered? mustn't he have engendered? mustn't we have engendered? mustn't you have engendered? mustn't they have engendered?
V-ing perfect
mustn't I have been engendering? mustn't you have been engendering? mustn't he have been engendering? mustn't we have been engendering? mustn't you have been engendering? mustn't they have been engendering?