must sharpen
Verbo regular: sharpen - sharpened- sharpened

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must sharpen
you must sharpen
she must sharpen
we must sharpen
you must sharpen
they must sharpen 	I must be sharpening
you must be sharpening
she must be sharpening
we must be sharpening
you must be sharpening
they must be sharpening	I must have sharpened
you must have sharpened
she must have sharpened
we must have sharpened
you must have sharpened
they must have sharpened	I must have been sharpening
you must have been sharpening
she must have been sharpening
we must have been sharpening
you must have been sharpening
they must have been sharpening	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not sharpen
you must not sharpen
she must not sharpen
we must not sharpen
you must not sharpen
they must not sharpen 	I must not be sharpening
you must not be sharpening
she must not be sharpening
we must not be sharpening
you must not be sharpening
they must not be sharpening	I must not have sharpened
you must not have sharpened
she must not have sharpened
we must not have sharpened
you must not have sharpened
they must not have sharpened	I must not have been sharpening
you must not have been sharpening
she must not have been sharpening
we must not have been sharpening
you must not have been sharpening
they must not have been sharpening	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I sharpen?
must you sharpen?
must she sharpen?
must we sharpen?
must you sharpen?
must they sharpen? 	must I be sharpening?
must you be sharpening?
must she be sharpening?
must we be sharpening?
must you be sharpening?
must they be sharpening? 	must I have sharpened?
must you have sharpened?
must she have sharpened?
must we have sharpened?
must you have sharpened?
must they have sharpened? 	must I have been sharpening?
must you have been sharpening?
must she have been sharpening?
must we have been sharpening?
must you have been sharpening?
must they have been sharpening? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not sharpen?
must you not sharpen?
must she not sharpen?
must we not sharpen?
must you not sharpen?
must they not sharpen? 	must I not be sharpening?
must you not be sharpening?
must she not be sharpening?
must we not be sharpening?
must you not be sharpening?
must they not be sharpening? 	must I not have sharpened?
must you not have sharpened?
must she not have sharpened?
must we not have sharpened?
must you not have sharpened?
must they not have sharpened? 	must I not have been sharpening?
must you not have been sharpening?
must she not have been sharpening?
must we not have been sharpening?
must you not have been sharpening?
must they not have been sharpening?