English verb conjugation
MUST CRASH

Regular verb: crash - crashed - crashed

Affirmation

Simple form	V-ing form
I must crash you must crash he must crash we must crash you must crash they must crash	I must be crashing you must be crashing he must be crashing we must be crashing you must be crashing they must be crashing
Perfect	V-ing perfect
I must have crashed you must have crashed he must have crashed we must have crashed you must have crashed they must have crashed	I must have been crashing you must have been crashing he must have been crashing we must have been crashing you must have been crashing they must have been crashing

Negation

Simple form	V-ing form
I must not crash you must not crash he must not crash we must not crash you must not crash they must not crash	I must not be crashing you must not be crashing he must not be crashing we must not be crashing you must not be crashing they must not be crashing
Perfect	V-ing perfect
I must not have crashed you must not have crashed he must not have crashed we must not have crashed you must not have crashed they must not have crashed	I must not have been crashing you must not have been crashing he must not have been crashing we must not have been crashing you must not have been crashing they must not have been crashing

Interrogative form

Simple form	V-ing form
must I crash? must you crash? must he crash? must we crash? must you crash? must they crash?	must I be crashing? must you be crashing? must he be crashing? must we be crashing? must you be crashing? must they be crashing?
Perfect	V-ing perfect
must I have crashed? must you have crashed? must he have crashed? must we have crashed? must you have crashed? must they have crashed?	must I have been crashing? must you have been crashing? must he have been crashing? must we have been crashing? must you have been crashing? must they have been crashing?

Interro-negative form

Simple form	V-ing form
must I not crash? must you not crash? must he not crash? must we not crash? must you not crash? must they not crash?	must I not be crashing? must you not be crashing? must he not be crashing? must we not be crashing? must you not be crashing? must they not be crashing?
Perfect	V-ing perfect
must I not have crashed? must you not have crashed? must he not have crashed? must we not have crashed? must you not have crashed? must they not have crashed?	must I not have been crashing? must you not have been crashing? must he not have been crashing? must we not have been crashing? must you not have been crashing? must they not have been crashing?