I must backstop you must backstop he must backstop we must backstop you must backstop they must backstop
Forme en V-ing
I must be backstoping you must be backstoping he must be backstoping we must be backstoping you must be backstoping they must be backstoping
Perfect
I must have backstoped you must have backstoped he must have backstoped we must have backstoped you must have backstoped they must have backstoped
Perfect en V-ing
I must have been backstoping you must have been backstoping he must have been backstoping we must have been backstoping you must have been backstoping they must have been backstoping
Négation
Forme simple
I mustn't backstop you mustn't backstop he mustn't backstop we mustn't backstop you mustn't backstop they mustn't backstop
Forme en V-ing
I mustn't be backstoping you mustn't be backstoping he mustn't be backstoping we mustn't be backstoping you mustn't be backstoping they mustn't be backstoping
Perfect
I mustn't have backstoped you mustn't have backstoped he mustn't have backstoped we mustn't have backstoped you mustn't have backstoped they mustn't have backstoped
Perfect en V-ing
I mustn't have been backstoping you mustn't have been backstoping he mustn't have been backstoping we mustn't have been backstoping you mustn't have been backstoping they mustn't have been backstoping
Forme interrogative
Forme simple
must I backstop? must you backstop? must he backstop? must we backstop? must you backstop? must they backstop?
Forme en V-ing
must I be backstoping? must you be backstoping? must he be backstoping? must we be backstoping? must you be backstoping? must they be backstoping?
Perfect
must I have backstoped? must you have backstoped? must he have backstoped? must we have backstoped? must you have backstoped? must they have backstoped?
Perfect en V-ing
must I have been backstoping? must you have been backstoping? must he have been backstoping? must we have been backstoping? must you have been backstoping? must they have been backstoping?
Forme interro-négative
Forme simple
mustn't I backstop? mustn't you backstop? mustn't he backstop? mustn't we backstop? mustn't you backstop? mustn't they backstop?
Forme en V-ing
mustn't I be backstoping? mustn't you be backstoping? mustn't he be backstoping? mustn't we be backstoping? mustn't you be backstoping? mustn't they be backstoping?
Perfect
mustn't I have backstoped? mustn't you have backstoped? mustn't he have backstoped? mustn't we have backstoped? mustn't you have backstoped? mustn't they have backstoped?
Perfect en V-ing
mustn't I have been backstoping? mustn't you have been backstoping? mustn't he have been backstoping? mustn't we have been backstoping? mustn't you have been backstoping? mustn't they have been backstoping?