English verb conjugation
MUST BURROW

Regular verb: burrow - burrowed - burrowed

Affirmation

Simple form	V-ing form
I must burrow you must burrow he must burrow we must burrow you must burrow they must burrow	I must be burrowing you must be burrowing he must be burrowing we must be burrowing you must be burrowing they must be burrowing
Perfect	V-ing perfect
I must have burrowed you must have burrowed he must have burrowed we must have burrowed you must have burrowed they must have burrowed	I must have been burrowing you must have been burrowing he must have been burrowing we must have been burrowing you must have been burrowing they must have been burrowing

Negation

Simple form	V-ing form
I mustn't burrow you mustn't burrow he mustn't burrow we mustn't burrow you mustn't burrow they mustn't burrow	I mustn't be burrowing you mustn't be burrowing he mustn't be burrowing we mustn't be burrowing you mustn't be burrowing they mustn't be burrowing
Perfect	V-ing perfect
I mustn't have burrowed you mustn't have burrowed he mustn't have burrowed we mustn't have burrowed you mustn't have burrowed they mustn't have burrowed	I mustn't have been burrowing you mustn't have been burrowing he mustn't have been burrowing we mustn't have been burrowing you mustn't have been burrowing they mustn't have been burrowing

Interrogative form

Simple form	V-ing form
must I burrow? must you burrow? must he burrow? must we burrow? must you burrow? must they burrow?	must I be burrowing? must you be burrowing? must he be burrowing? must we be burrowing? must you be burrowing? must they be burrowing?
Perfect	V-ing perfect
must I have burrowed? must you have burrowed? must he have burrowed? must we have burrowed? must you have burrowed? must they have burrowed?	must I have been burrowing? must you have been burrowing? must he have been burrowing? must we have been burrowing? must you have been burrowing? must they have been burrowing?

Interro-negative form

Simple form	V-ing form
mustn't I burrow? mustn't you burrow? mustn't he burrow? mustn't we burrow? mustn't you burrow? mustn't they burrow?	mustn't I be burrowing? mustn't you be burrowing? mustn't he be burrowing? mustn't we be burrowing? mustn't you be burrowing? mustn't they be burrowing?
Perfect	V-ing perfect
mustn't I have burrowed? mustn't you have burrowed? mustn't he have burrowed? mustn't we have burrowed? mustn't you have burrowed? mustn't they have burrowed?	mustn't I have been burrowing? mustn't you have been burrowing? mustn't he have been burrowing? mustn't we have been burrowing? mustn't you have been burrowing? mustn't they have been burrowing?