English verb conjugation
MUST LUMBER

Regular verb: lumber - lumbered - lumbered

Affirmation

Simple form	V-ing form
I must lumber you must lumber he must lumber we must lumber you must lumber they must lumber	I must be lumbering you must be lumbering he must be lumbering we must be lumbering you must be lumbering they must be lumbering
Perfect	V-ing perfect
I must have lumbered you must have lumbered he must have lumbered we must have lumbered you must have lumbered they must have lumbered	I must have been lumbering you must have been lumbering he must have been lumbering we must have been lumbering you must have been lumbering they must have been lumbering

Negation

Simple form	V-ing form
I mustn't lumber you mustn't lumber he mustn't lumber we mustn't lumber you mustn't lumber they mustn't lumber	I mustn't be lumbering you mustn't be lumbering he mustn't be lumbering we mustn't be lumbering you mustn't be lumbering they mustn't be lumbering
Perfect	V-ing perfect
I mustn't have lumbered you mustn't have lumbered he mustn't have lumbered we mustn't have lumbered you mustn't have lumbered they mustn't have lumbered	I mustn't have been lumbering you mustn't have been lumbering he mustn't have been lumbering we mustn't have been lumbering you mustn't have been lumbering they mustn't have been lumbering

Interrogative form

Simple form	V-ing form
must I lumber? must you lumber? must he lumber? must we lumber? must you lumber? must they lumber?	must I be lumbering? must you be lumbering? must he be lumbering? must we be lumbering? must you be lumbering? must they be lumbering?
Perfect	V-ing perfect
must I have lumbered? must you have lumbered? must he have lumbered? must we have lumbered? must you have lumbered? must they have lumbered?	must I have been lumbering? must you have been lumbering? must he have been lumbering? must we have been lumbering? must you have been lumbering? must they have been lumbering?

Interro-negative form

Simple form	V-ing form
mustn't I lumber? mustn't you lumber? mustn't he lumber? mustn't we lumber? mustn't you lumber? mustn't they lumber?	mustn't I be lumbering? mustn't you be lumbering? mustn't he be lumbering? mustn't we be lumbering? mustn't you be lumbering? mustn't they be lumbering?
Perfect	V-ing perfect
mustn't I have lumbered? mustn't you have lumbered? mustn't he have lumbered? mustn't we have lumbered? mustn't you have lumbered? mustn't they have lumbered?	mustn't I have been lumbering? mustn't you have been lumbering? mustn't he have been lumbering? mustn't we have been lumbering? mustn't you have been lumbering? mustn't they have been lumbering?