Solo haz lo que tengas que hacer.

[cityotter]

English Translation

Just do what you have to do.

Does anyone understand what prompted the subjunctive form of tener in this sentence??

[IlliniPatT]

not native speaker but I think it is a recommendation

[morbrorper]

I would say the subjunctive reflects uncertainty: it’s not yet known what you will (possibly) have to do.

[cdemora]

“Just do whatever you have to do.”