English verb conjugation
MUST SKULK

Regular verb: skulk - skulked - skulked

Affirmation

Simple form	V-ing form
I must skulk you must skulk he must skulk we must skulk you must skulk they must skulk	I must be skulking you must be skulking he must be skulking we must be skulking you must be skulking they must be skulking
Perfect	V-ing perfect
I must have skulked you must have skulked he must have skulked we must have skulked you must have skulked they must have skulked	I must have been skulking you must have been skulking he must have been skulking we must have been skulking you must have been skulking they must have been skulking

Negation

Simple form	V-ing form
I must not skulk you must not skulk he must not skulk we must not skulk you must not skulk they must not skulk	I must not be skulking you must not be skulking he must not be skulking we must not be skulking you must not be skulking they must not be skulking
Perfect	V-ing perfect
I must not have skulked you must not have skulked he must not have skulked we must not have skulked you must not have skulked they must not have skulked	I must not have been skulking you must not have been skulking he must not have been skulking we must not have been skulking you must not have been skulking they must not have been skulking

Interrogative form

Simple form	V-ing form
must I skulk? must you skulk? must he skulk? must we skulk? must you skulk? must they skulk?	must I be skulking? must you be skulking? must he be skulking? must we be skulking? must you be skulking? must they be skulking?
Perfect	V-ing perfect
must I have skulked? must you have skulked? must he have skulked? must we have skulked? must you have skulked? must they have skulked?	must I have been skulking? must you have been skulking? must he have been skulking? must we have been skulking? must you have been skulking? must they have been skulking?

Interro-negative form

Simple form	V-ing form
must I not skulk? must you not skulk? must he not skulk? must we not skulk? must you not skulk? must they not skulk?	must I not be skulking? must you not be skulking? must he not be skulking? must we not be skulking? must you not be skulking? must they not be skulking?
Perfect	V-ing perfect
must I not have skulked? must you not have skulked? must he not have skulked? must we not have skulked? must you not have skulked? must they not have skulked?	must I not have been skulking? must you not have been skulking? must he not have been skulking? must we not have been skulking? must you not have been skulking? must they not have been skulking?