must tinker
Regular verb: tinker - tinkered- tinkered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must tinker
you must tinker
she must tinker
we must tinker
you must tinker
they must tinker 	I must be tinkering
you must be tinkering
she must be tinkering
we must be tinkering
you must be tinkering
they must be tinkering	I must have tinkered
you must have tinkered
she must have tinkered
we must have tinkered
you must have tinkered
they must have tinkered	I must have been tinkering
you must have been tinkering
she must have been tinkering
we must have been tinkering
you must have been tinkering
they must have been tinkering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not tinker
you must not tinker
she must not tinker
we must not tinker
you must not tinker
they must not tinker 	I must not be tinkering
you must not be tinkering
she must not be tinkering
we must not be tinkering
you must not be tinkering
they must not be tinkering	I must not have tinkered
you must not have tinkered
she must not have tinkered
we must not have tinkered
you must not have tinkered
they must not have tinkered	I must not have been tinkering
you must not have been tinkering
she must not have been tinkering
we must not have been tinkering
you must not have been tinkering
they must not have been tinkering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I tinker?
must you tinker?
must she tinker?
must we tinker?
must you tinker?
must they tinker? 	must I be tinkering?
must you be tinkering?
must she be tinkering?
must we be tinkering?
must you be tinkering?
must they be tinkering? 	must I have tinkered?
must you have tinkered?
must she have tinkered?
must we have tinkered?
must you have tinkered?
must they have tinkered? 	must I have been tinkering?
must you have been tinkering?
must she have been tinkering?
must we have been tinkering?
must you have been tinkering?
must they have been tinkering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not tinker?
must you not tinker?
must she not tinker?
must we not tinker?
must you not tinker?
must they not tinker? 	must I not be tinkering?
must you not be tinkering?
must she not be tinkering?
must we not be tinkering?
must you not be tinkering?
must they not be tinkering? 	must I not have tinkered?
must you not have tinkered?
must she not have tinkered?
must we not have tinkered?
must you not have tinkered?
must they not have tinkered? 	must I not have been tinkering?
must you not have been tinkering?
must she not have been tinkering?
must we not have been tinkering?
must you not have been tinkering?
must they not have been tinkering?