An -um- verb belongs to an actor-voice family, but actor voice does not tell you how many participants the verb has or guarantee that its pivot is a deliberate human agent. Tumakbo is commonly one-participant, bumili can relate a buyer to a thing bought, and bumukas can present an inanimate door as undergoing a spontaneous change.
That participant capacity is valency. It is partly lexical: learners must know not just a root and an affix, but the established construction, its meaning, and the markers licensed for each participant.
The basic marker alignment is introduced in marker choice with actor-voice verbs. This page goes further by asking why different -um- lexemes license different participant frames.
A compact map of common frames
| Frame | Example family | Pivot | Other participant |
|---|---|---|---|
| motion/activity | tumakbo | ang/si mover | optional path or goal with sa |
| motion toward a goal | pumunta | ang/si mover | goal with sa/kay |
| transitive acquisition | bumili | ang/si buyer | thing bought with ng |
| production/communication | sumulat | ang/si writer | text with ng; addressee with sa/kay |
| change of state | bumukas | ang changing entity | often no core second participant |
| weather event | umulan | normally no overt actor | optional place/time setting |
These frames are neutral contemporary standard Filipino. They are not meanings contributed by -um- alone; they are meanings of particular lexical families.
-Um- verbs may be intransitive or transitive
An intransitive frame has no core patient. Destinations and locations are normally oblique.
Tumakbo ang mga boluntaryo papunta sa malaking pasilungan nang magsimulang umulan.
The volunteers ran toward the large shelter when it began to rain.
Ang mga boluntaryo is the actor pivot. Papunta sa malaking pasilungan is a directional phrase, not a patient. Weather verb umulan has no deliberate actor at all.
Other -um- verbs license a core theme or patient marked by ng.
Bumili si Farah ng mga kumot para sa sentro ng paglikas.
Farah bought blankets for the evacuation center.
Sumulat ang doktor ng sertipiko para sa pasyente.
The doctor wrote a certificate for the patient.
The actor pivots are si Farah and ang doktor. Ng mga kumot and ng sertipiko are non-pivot core participants. The existence of a patient does not make the verb patient voice.
The pivot is not always an intentional agent
The term actor covers the privileged participant of the voice construction, but lexical semantics may identify that participant as a mover, experiencer, or changing entity rather than a conscious doer.
Bumukas ang bintana dahil sa malakas na hangin.
The window opened because of the strong wind.
Luminis ang tubig matapos salain nang dalawang beses.
The water became clear after being filtered twice.
The window and water are inanimate pivots in change-of-state events. No hidden person intentionally performs bumukas or luminis. Nang dalawang beses is an adverbial frequency expression; it is distinct from marker ng.
This matters because an English learner may equate actor voice with English active clauses containing an agent. Filipino voice is grammatical alignment, while animacy and control come from the lexical predicate and context.
Affix choice can change valency and event structure
Compare related constructions from bukas:
Bumukas ang pinto nang lumakas ang hangin.
The door opened when the wind grew stronger.
Nagbukas si Leon ng pinto para pumasok ang hangin.
Leon opened a door to let air in.
Binuksan ni Leon ang pinto para pumasok ang hangin.
Leon opened the door to let air in.
Bumukas construes the door's change of state and takes that changing entity as pivot. Nagbukas introduces Leon as actor pivot and a door as ng-marked patient. Binuksan selects the door as patient pivot and marks Leon with ni. English uses “open” for all three, hiding both the valency contrast and the Filipino voice alignment.
A comparable contrast occurs with linis: luminis ang silid means that the room became clean, while naglinis si Eva ng silid means that Eva performed cleaning. It would be inaccurate to reduce -um- to “intransitive” or mag- to “transitive,” because verbs such as bumili and sumulat show that -um- can itself license a second core participant.
Definiteness does not mechanically determine valency or voice
Actor-voice patients are often nonspecific in everyday discourse, but ng does not mean “indefinite article.” A highly identifiable patient can remain non-pivot.
Bumili si Farah ng kumot na itinabi ng tindera para sa kaniya.
Farah bought the blanket that the vendor had set aside for her.
The relative clause makes the blanket identifiable. It remains ng-marked because Farah is the pivot of actor-voice bumili. Speakers may prefer patient voice when a particular affected entity is the center of the discourse, but definiteness alone does not allow ang to replace ng after an actor-voice verb.
The full choice between voices also depends on affectedness, information structure, question type, and the lexical verb. Those discourse conditions deserve separate treatment; the structural requirement here is that verb voice and phrase markers form one package.
Personal endpoints and oblique participants
English calls many different participants “objects.” Filipino separates core ng phrases from oblique destinations and personal endpoints.
Tumawag si Liza kay Mang Nestor para kumpirmahin ang oras.
Liza called Mang Nestor to confirm the time.
With actor-voice tumawag, the contacted person is conventionally expressed as a personal oblique with kay, not as ni Mang Nestor. A nonpersonal office would take sa, as in tumawag sa tanggapan.
—Pumunta ba si Iris kay Aling Rosa kahapon? —Hindi, pumunta siya sa klinika para magpatingin.
—Did Iris go to Aling Rosa's place yesterday? —No, she went to the clinic for a consultation.
The exchange contrasts personal destination kay Aling Rosa with nonpersonal destination sa klinika. Both are obliques licensed by motion verb pumunta, while si Iris/siya remains pivot.
Lexical restrictions and variation
A root is a family of constructions, and one citation form hides the derivational system. Knowing luto does not predict lumuto; ordinary actor voice uses magluto. Knowing bukas does not mean that bumukas, nagbukas, and binuksan are interchangeable. Their valency and alignment differ.
Some roots allow accepted variation. Bumiyahe and nagbiyahe both occur in contemporary Filipino for “travel,” with preferences differing across speakers and collocations. Other apparent alternatives divide meanings: sumagot normally means “respond,” while magsagot commonly means answering a set of questions or filling in answers. There is no honest universal paraphrase such as “-um- means spontaneous” or “mag- means deliberate.”
The productive pattern is therefore constrained twice: morphology builds aspect forms inside an attested family, and the lexicon determines which family-and-frame combinations are established.
Common Mistakes
Treating -um- as a universal actor-voice affix
❌ Lumuto si Mila ng isda para sa tanghalian.
Incorrect in neutral standard Filipino — the ordinary actor-voice family of luto uses mag-/nag-.
✅ Nagluto si Mila ng isda para sa tanghalian.
Mila cooked fish for lunch.
The correction selects an attested lexical family; it is not a mere spelling adjustment.
Giving an agent to spontaneous bumukas with ni
❌ Bumukas ni Lara ang bintana bago matulog.
Incorrect for ‘Lara opened the window’ — bumukas construes the window itself as undergoing the change.
✅ Binuksan ni Lara ang bintana bago matulog.
Lara opened the window before going to sleep.
Patient-voice binuksan licenses ni Lara as non-pivot actor and ang bintana as patient pivot. Actor voice Nagbukas si Lara ng bintana is another grammatical alignment.
Marking the patient as a second pivot
❌ Bumili si Jared ang gamot na inireseta ng doktor.
Incorrect — actor-voice bumili selects Jared as pivot, so its core patient cannot also take ang.
✅ Bumili si Jared ng gamot na inireseta ng doktor.
Jared bought the medicine prescribed by the doctor.
Specific ng gamot na inireseta ng doktor is grammatical. Specificity does not override voice.
Treating a personal endpoint as an ng/ni object
❌ Tumawag si Nena ni Kapitan Reyes para itanong ang iskedyul.
Incorrect — ni marks a named non-pivot actor or possessor, not the endpoint of actor-voice tumawag.
✅ Tumawag si Nena kay Kapitan Reyes para itanong ang iskedyul.
Nena called Captain Reyes to ask about the schedule.
The lexical frame of tumawag selects the contacted person with personal oblique kay.
Key Takeaways
- -Um- actor voice occurs in both one-participant and transitive constructions.
- The pivot may be an agent, mover, changing entity, or other actor-like participant; it need not be animate or volitional.
- Each lexical verb determines its valency and the markers used for patients, goals, and endpoints.
- Affix contrasts can change event structure as well as voice: bumukas, nagbukas, and binuksan are different constructions.
- Learn roots as construction families with attested forms, meanings, and participant frames.
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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.
- Roots, Affixes, and Verb WordsA2 — See how Filipino roots combine with prefixes, infixes, suffixes, and reduplication to form lexical verb families marked for voice and aspect.
- Valency and Participant StructureA2 — Map the actors, patients, recipients, locations, beneficiaries, and instruments licensed by Filipino verb constructions and their voice frames.
- 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.
- Actor VoiceB1 — Use actor voice to select an actor, experiencer, or moving participant as pivot while marking patients and obliques appropriately.
- Patient VoiceB1 — Use patient voice to select an affected or delimited participant as pivot while retaining the actor as a core ng-series phrase.