English verb conjugation
MUST DULL

Regular verb: dull - dulled - dulled

Affirmation

Simple form	V-ing form
I must dull you must dull he must dull we must dull you must dull they must dull	I must be dulling you must be dulling he must be dulling we must be dulling you must be dulling they must be dulling
Perfect	V-ing perfect
I must have dulled you must have dulled he must have dulled we must have dulled you must have dulled they must have dulled	I must have been dulling you must have been dulling he must have been dulling we must have been dulling you must have been dulling they must have been dulling

Negation

Simple form	V-ing form
I must not dull you must not dull he must not dull we must not dull you must not dull they must not dull	I must not be dulling you must not be dulling he must not be dulling we must not be dulling you must not be dulling they must not be dulling
Perfect	V-ing perfect
I must not have dulled you must not have dulled he must not have dulled we must not have dulled you must not have dulled they must not have dulled	I must not have been dulling you must not have been dulling he must not have been dulling we must not have been dulling you must not have been dulling they must not have been dulling

Interrogative form

Simple form	V-ing form
must I dull? must you dull? must he dull? must we dull? must you dull? must they dull?	must I be dulling? must you be dulling? must he be dulling? must we be dulling? must you be dulling? must they be dulling?
Perfect	V-ing perfect
must I have dulled? must you have dulled? must he have dulled? must we have dulled? must you have dulled? must they have dulled?	must I have been dulling? must you have been dulling? must he have been dulling? must we have been dulling? must you have been dulling? must they have been dulling?

Interro-negative form

Simple form	V-ing form
must I not dull? must you not dull? must he not dull? must we not dull? must you not dull? must they not dull?	must I not be dulling? must you not be dulling? must he not be dulling? must we not be dulling? must you not be dulling? must they not be dulling?
Perfect	V-ing perfect
must I not have dulled? must you not have dulled? must he not have dulled? must we not have dulled? must you not have dulled? must they not have dulled?	must I not have been dulling? must you not have been dulling? must he not have been dulling? must we not have been dulling? must you not have been dulling? must they not have been dulling?