English verb conjugation
MUST BACKSOLVE

Regular verb: backsolve - backsolved - backsolved

Affirmation

Simple form	V-ing form
I must backsolve you must backsolve he must backsolve we must backsolve you must backsolve they must backsolve	I must be backsolving you must be backsolving he must be backsolving we must be backsolving you must be backsolving they must be backsolving
Perfect	V-ing perfect
I must have backsolved you must have backsolved he 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 he must have been backsolving we must have been backsolving you must have been backsolving they must have been backsolving

Negation

Simple form	V-ing form
I mustn't backsolve you mustn't backsolve he mustn't backsolve we mustn't backsolve you mustn't backsolve they mustn't backsolve	I mustn't be backsolving you mustn't be backsolving he mustn't be backsolving we mustn't be backsolving you mustn't be backsolving they mustn't be backsolving
Perfect	V-ing perfect
I mustn't have backsolved you mustn't have backsolved he mustn't have backsolved we mustn't have backsolved you mustn't have backsolved they mustn't have backsolved	I mustn't have been backsolving you mustn't have been backsolving he mustn't have been backsolving we mustn't have been backsolving you mustn't have been backsolving they mustn't have been backsolving

Interrogative form

Simple form	V-ing form
must I backsolve? must you backsolve? must he backsolve? must we backsolve? must you backsolve? must they backsolve?	must I be backsolving? must you be backsolving? must he be backsolving? must we be backsolving? must you be backsolving? must they be backsolving?
Perfect	V-ing perfect
must I have backsolved? must you have backsolved? must he 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 he have been backsolving? must we have been backsolving? must you have been backsolving? must they have been backsolving?

Interro-negative form

Simple form	V-ing form
mustn't I backsolve? mustn't you backsolve? mustn't he backsolve? mustn't we backsolve? mustn't you backsolve? mustn't they backsolve?	mustn't I be backsolving? mustn't you be backsolving? mustn't he be backsolving? mustn't we be backsolving? mustn't you be backsolving? mustn't they be backsolving?
Perfect	V-ing perfect
mustn't I have backsolved? mustn't you have backsolved? mustn't he have backsolved? mustn't we have backsolved? mustn't you have backsolved? mustn't they have backsolved?	mustn't I have been backsolving? mustn't you have been backsolving? mustn't he have been backsolving? mustn't we have been backsolving? mustn't you have been backsolving? mustn't they have been backsolving?