must singe
Regular verb: singe - singed- singed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must singe
you must singe
she must singe
we must singe
you must singe
they must singe 	I must be singing
you must be singing
she must be singing
we must be singing
you must be singing
they must be singing	I must have singed
you must have singed
she must have singed
we must have singed
you must have singed
they must have singed	I must have been singing
you must have been singing
she must have been singing
we must have been singing
you must have been singing
they must have been singing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not singe
you must not singe
she must not singe
we must not singe
you must not singe
they must not singe 	I must not be singing
you must not be singing
she must not be singing
we must not be singing
you must not be singing
they must not be singing	I must not have singed
you must not have singed
she must not have singed
we must not have singed
you must not have singed
they must not have singed	I must not have been singing
you must not have been singing
she must not have been singing
we must not have been singing
you must not have been singing
they must not have been singing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I singe?
must you singe?
must she singe?
must we singe?
must you singe?
must they singe? 	must I be singing?
must you be singing?
must she be singing?
must we be singing?
must you be singing?
must they be singing? 	must I have singed?
must you have singed?
must she have singed?
must we have singed?
must you have singed?
must they have singed? 	must I have been singing?
must you have been singing?
must she have been singing?
must we have been singing?
must you have been singing?
must they have been singing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not singe?
must you not singe?
must she not singe?
must we not singe?
must you not singe?
must they not singe? 	must I not be singing?
must you not be singing?
must she not be singing?
must we not be singing?
must you not be singing?
must they not be singing? 	must I not have singed?
must you not have singed?
must she not have singed?
must we not have singed?
must you not have singed?
must they not have singed? 	must I not have been singing?
must you not have been singing?
must she not have been singing?
must we not have been singing?
must you not have been singing?
must they not have been singing?