must riffle
Regular verb: riffle - riffled- riffled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must riffle
you must riffle
he must riffle
we must riffle
you must riffle
they must riffle 	I must be riffling
you must be riffling
he must be riffling
we must be riffling
you must be riffling
they must be riffling	I must have riffled
you must have riffled
he must have riffled
we must have riffled
you must have riffled
they must have riffled	I must have been riffling
you must have been riffling
he must have been riffling
we must have been riffling
you must have been riffling
they must have been riffling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not riffle
you must not riffle
he must not riffle
we must not riffle
you must not riffle
they must not riffle 	I must not be riffling
you must not be riffling
he must not be riffling
we must not be riffling
you must not be riffling
they must not be riffling	I must not have riffled
you must not have riffled
he must not have riffled
we must not have riffled
you must not have riffled
they must not have riffled	I must not have been riffling
you must not have been riffling
he must not have been riffling
we must not have been riffling
you must not have been riffling
they must not have been riffling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I riffle?
must you riffle?
must he riffle?
must we riffle?
must you riffle?
must they riffle? 	must I be riffling?
must you be riffling?
must he be riffling?
must we be riffling?
must you be riffling?
must they be riffling? 	must I have riffled?
must you have riffled?
must he have riffled?
must we have riffled?
must you have riffled?
must they have riffled? 	must I have been riffling?
must you have been riffling?
must he have been riffling?
must we have been riffling?
must you have been riffling?
must they have been riffling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not riffle?
must you not riffle?
must he not riffle?
must we not riffle?
must you not riffle?
must they not riffle? 	must I not be riffling?
must you not be riffling?
must he not be riffling?
must we not be riffling?
must you not be riffling?
must they not be riffling? 	must I not have riffled?
must you not have riffled?
must he not have riffled?
must we not have riffled?
must you not have riffled?
must they not have riffled? 	must I not have been riffling?
must you not have been riffling?
must he not have been riffling?
must we not have been riffling?
must you not have been riffling?
must they not have been riffling?