Both -um- and mag- form major actor-voice families, but they are not interchangeable labels for English “do” or “act.” Choose the established family of the Filipino root. When one root permits both, the two forms may differ in valency or conventional meaning, or they may overlap in a restricted set of contexts.
Semantic tendencies help organize vocabulary: -um- is common with motion, change, and many basic actions; mag- is common with activities, occupations, reciprocal events, borrowed bases, and actions involving a product. These are tendencies, never an automatic derivation rule. All unlabelled examples below are neutral contemporary Filipino.
The quick comparison
| Decision point | -um- family | mag- family |
|---|---|---|
| Voice | actor voice | actor voice |
| Basic/completed shape | bumili, umalis, sumagot | magluto/nagluto, mag-aral/nag-aral |
| Frequent lexical territory | motion, change of state, response, consumption, acquisition | deliberate/sustained activity, work, reciprocal action, production |
| Patient under actor voice | commonly ng, if licensed | commonly ng, if licensed |
| Most reliable rule | learn the root's attested family and participant frame | |
Neither affix marks English tense. Each expands into an aspect paradigm: bumili—bumibili—bibili and nagluto—nagluluto—magluluto.
Step 1: learn the default family with the root
Some high-frequency roots strongly select one ordinary actor-voice family.
Dumating ang dentista bago magbukas ang klinika.
The dentist arrived before the clinic opened. (-um- family of dating)
Nagluto si Belen ng ginataang kalabasa para sa mga bisita.
Belen cooked squash in coconut milk for the guests. (mag- family of luto)
Standard neutral Filipino uses dumating, not invented magdating, for simple arrival, and nagluto, not lumuto, for completed cooking. English supplies no clue to this lexical membership.
The full -um- family guide and mag- family guide provide their paradigms.
Step 2: when both exist, inspect valency
With some roots, the contrast changes how many participants the event has. Umakyat presents the mover going up; mag-akyat presents an actor taking something upward.
Umakyat si Lando sa tore para tingnan ang lumang kampana.
Lando climbed the tower to inspect the old bell. (-um-; mover as pivot)
Nag-akyat si Lando ng dalawang lubid sa tore bago dumilim.
Lando carried two ropes up the tower before dark. (mag-; actor plus moved theme)
The goal remains a sa phrase in both. Only the mag- construction here licenses ng dalawang lubid as the moved theme. The difference is not simply accidental versus intentional.
The bukas family shows a similar event-structure contrast:
Kusang bumukas ang lumang tarangkahan nang lumakas ang hangin.
The old gate opened on its own when the wind grew stronger. (-um- change of state)
Nagbukas ang guwardiya ng maliit na tarangkahan para sa mga bisikleta.
The guard opened a small gate for bicycles. (mag- actor-caused event)
Bumukas selects the changing entity as its sole pivot. Nagbukas selects the actor and adds a non-pivot patient. That contrast belongs to this root family; it is not a universal definition of the affixes.
Step 3: inspect the conventional kind of action
Two forms from sagot distinguish responding from working through answerable items:
Sumagot si Dina sa tanong ng mamamahayag nang maikli.
Dina answered the journalist's question briefly. (-um-; respond)
Nagsagot si Dina ng sampung tanong sa aplikasyon.
Dina answered ten questions on the application. (mag-; work through items)
The contrast is lexical and constructional. Sumagot normally relates the response to sa tanong or an interlocutor; magsagot readily takes ng items. English answer hides the distinction.
With sulat, the meanings overlap more:
Sumulat si Ramon kay Tita Cely para magpasalamat sa padala.
Ramon wrote to Aunt Cely to thank her for the package. (-um-; correspondence)
Nagsulat si Ramon ng maikling tala sa likod ng resibo.
Ramon wrote a short note on the back of the receipt. (mag-; produce a text)
Sumulat readily foregrounds correspondence or the act of writing; magsulat readily takes a produced text. Actual usage overlaps, so these are useful frames rather than absolute definitions.
Step 4: do not confuse family choice with aspect
Once the family is selected, choose aspect within it.
| Family | Completed | Incompleted | Contemplated |
|---|---|---|---|
| -um-: bili | bumili | bumibili | bibili |
| mag-: luto | nagluto | nagluluto | magluluto |
| -um-: alis | umalis | umaalis | aalis |
| mag-: aral | nag-aral | nag-aaral | mag-aaral |
Hindi pa umaalis ang huling bus; alas-nuwebe pa lamang.
The last bus hasn't left yet; it is only nine o'clock. (incompleted -um- family under negation)
The negative hindi pa does not trigger mag-. Voice family is lexical; aspect and polarity are separate choices.
Accepted overlap and variation
Some roots have two accepted actor-voice patterns without a sharp universal contrast. Lumakad and maglakad both occur for walking; bumiyahe and magbiyahe both occur for traveling. Preferences vary by speaker, region, collocation, and construction.
Mas gusto naming maglakad pauwi kapag malamig ang hangin.
We prefer to walk home when the air is cool. (neutral accepted mag- form)
Lumakad sila nang dahan-dahan sa madulas na daan.
They walked slowly along the slippery road. (neutral accepted -um- form)
This root-specific overlap does not allow learners to create lumuto or magdating. Label regional preferences when known; do not stigmatize an established alternative merely to force a neat rule.
Register and discourse
Both families occur in conversation and formal prose. Conversation may omit a recoverable patient, goal, or actor, while careful writing often states a full frame such as sumagot sa tanong or magsagot ng mga tanong to prevent ambiguity. Register can affect which established collocation a speaker prefers, but it cannot license an invented family. Discourse prominence likewise helps choose among valid constructions only after their lexical meaning and valency fit the event.
A short exchange
—Sino ang mag-aakyat ng mga upuan sa entablado? —Ako na; umakyat ka muna at buksan mo ang ilaw.
—Who will take the chairs up to the stage? —I will; you go up first and turn on the light. (mag-akyat carries items; umakyat moves upward)
The exchange places both families in the contexts that distinguish them. Mag-aakyat has a theme, while umakyat does not.
Decision flow
- Look up the root's established actor-voice family.
- If both occur, compare their participant frames and conventional meanings.
- Choose aspect inside that family; do not use mag- as a future marker.
- Mark the actor pivot with ang/si and any licensed patient with ng.
- Treat overlap as root-specific variation, not a general affix swap.
Common Mistakes
Inventing -um- from the English meaning
❌ Lumuto si Belen ng sopas para sa batang may lagnat.
Incorrect in neutral standard Filipino — luto uses the ordinary mag- actor-voice family.
✅ Nagluto si Belen ng sopas para sa batang may lagnat.
Belen cooked soup for the child with a fever.
Using mag- for every deliberate action
❌ Nagdating ang mga panauhin bago magsimula ang programa.
Incorrect for simple arrival — the conventional actor-voice form is dumating.
✅ Dumating ang mga panauhin bago magsimula ang programa.
The guests arrived before the program began.
Treating mag- as a future prefix
❌ Magbibili si Olan ng pintura pagkatapos ng trabaho.
Wrong in neutral standard Filipino for the intended meaning 'buy' — the contemplated form in the bumili family is bibili.
✅ Bibili si Olan ng pintura pagkatapos ng trabaho.
Olan will buy paint after work.
Magbibili is therefore not an impossible word. It can belong to a separate, less common lexical family meaning “sell” or “deal in,” and regional colloquial usage also extends forms of magbili to “buy.” For neutral standard buying, use bumili—bumibili—bibili. This lexical and regional variation is exactly why mag- cannot be added mechanically as a future marker.
Ignoring the valency difference
❌ Nag-akyat si Lando sa tore para tingnan ang kampana.
Incorrect for the intended meaning that Lando himself climbed; this mag- frame calls for something taken upward.
✅ Umakyat si Lando sa tore para tingnan ang kampana.
Lando climbed the tower to inspect the bell.
Key Takeaways
-Um- and mag- both mark actor voice, so marker alignment does not decide between them. The root's lexical family does. Recurring meanings can help memory, while same-root pairs such as umakyat/mag-akyat, bumukas/magbukas, and sumagot/magsagot show that event structure and valency are often decisive. Choose the family first, aspect second, and treat accepted doublets as specific facts of usage.
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Start learning Filipino →Related Topics
- The -um- actor voice: Function and DistributionB1 — Learn where -um- appears, how it marks actor voice, and why its distribution must be learned with each Filipino root.
- The mag- actor voice: Function and DistributionB1 — Understand what mag- actor-voice verbs contribute, where they occur, and why their meanings must be learned as lexical families.
- Productive versus Lexicalized AffixesA2 — Learn when Filipino verb affixes support new formations and when an affixed verb's established meaning and participant frame must be learned as a unit.
- Multiple Possible Verbs from One RootA2 — Explore how one Filipino root can support several established verbs with different voices, participant frames, aspect paradigms, and lexical meanings.
- Marker Choice with Actor-Voice VerbsA1 — Choose ang, ng, and sa phrases with actor-voice verbs by identifying the actor pivot, core patient, and oblique participants.
- Choosing mag- and -um- by Meaning AloneB1 — Avoid invented actor-voice forms by learning each root's conventional mag- or -um- family, valency, and aspect paradigm.