For a fire, a liquid (actor muɴ- & inst) to intensively boil something cooking (theme i-).
pumūhol
Manghānom nan apuy ti nen pun'ipūholna nan bogah at mitapal.
Reduce the fire because it is extensively and intensively boiling the rice and so it will be spilled.
For a liquid, something being boiled (actor -um- & theme) to boil intensively.
Manghānom han apuy ti ten pumuhol han nihāang.
Lessen the fire because you see that which is cooked is boiling intensively.