must backsolve
Verbo regular: backsolve - backsolved- backsolved

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must backsolve
you must backsolve
she must backsolve
we must backsolve
you must backsolve
they must backsolve 	I must be backsolving
you must be backsolving
she must be backsolving
we must be backsolving
you must be backsolving
they must be backsolving	I must have backsolved
you must have backsolved
she must have backsolved
we must have backsolved
you must have backsolved
they must have backsolved	I must have been backsolving
you must have been backsolving
she must have been backsolving
we must have been backsolving
you must have been backsolving
they must have been backsolving	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not backsolve
you must not backsolve
she must not backsolve
we must not backsolve
you must not backsolve
they must not backsolve 	I must not be backsolving
you must not be backsolving
she must not be backsolving
we must not be backsolving
you must not be backsolving
they must not be backsolving	I must not have backsolved
you must not have backsolved
she must not have backsolved
we must not have backsolved
you must not have backsolved
they must not have backsolved	I must not have been backsolving
you must not have been backsolving
she must not have been backsolving
we must not have been backsolving
you must not have been backsolving
they must not have been backsolving	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I backsolve?
must you backsolve?
must she backsolve?
must we backsolve?
must you backsolve?
must they backsolve? 	must I be backsolving?
must you be backsolving?
must she be backsolving?
must we be backsolving?
must you be backsolving?
must they be backsolving? 	must I have backsolved?
must you have backsolved?
must she have backsolved?
must we have backsolved?
must you have backsolved?
must they have backsolved? 	must I have been backsolving?
must you have been backsolving?
must she have been backsolving?
must we have been backsolving?
must you have been backsolving?
must they have been backsolving? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not backsolve?
must you not backsolve?
must she not backsolve?
must we not backsolve?
must you not backsolve?
must they not backsolve? 	must I not be backsolving?
must you not be backsolving?
must she not be backsolving?
must we not be backsolving?
must you not be backsolving?
must they not be backsolving? 	must I not have backsolved?
must you not have backsolved?
must she not have backsolved?
must we not have backsolved?
must you not have backsolved?
must they not have backsolved? 	must I not have been backsolving?
must you not have been backsolving?
must she not have been backsolving?
must we not have been backsolving?
must you not have been backsolving?
must they not have been backsolving?