The -um- family is one of the central actor-voice patterns of contemporary standard Filipino. In an actor-voice clause, the actor is the pivot and normally takes ang or si, while a core theme or patient is commonly marked by ng. The affix does not translate as one English word: the root and the whole construction supply the event meaning.
The hard part is distribution. -Um- is productive within established families such as kumain, bumili, sumulat, tumakbo, and umalis, but it cannot be inserted into every root that English treats as a verb. Learning luto “cooking” does not license unattested lumuto for neutral “cook”; the ordinary actor-voice family is magluto, nagluto, nagluluto, magluluto.
If roots, infixes, and reduplication are new to you, begin with roots, affixes, and verb words. This page applies that framework specifically to the -um- family.
Position and function
With a consonant-initial root, -um- is inserted before the first vowel; in the common root shapes illustrated here, that places it after the initial consonant. With a vowel-initial root, it appears at the beginning as um-. Established words are written without teaching hyphens.
| Root shape | Root | Basic/completed form | Function in a clause |
|---|---|---|---|
| consonant-initial | kain | kumain | actor voice; actor is pivot |
| consonant-initial | bili | bumili | actor voice; buyer is pivot |
| consonant-initial | sulat | sumulat | actor voice; writer is pivot |
| vowel-initial | alis | umalis | actor voice; departing participant is pivot |
| vowel-initial | akyat | umakyat | actor voice; ascending participant is pivot |
Sumulat si Beatriz ng maikling tala para sa bagong kasamahan.
Beatriz wrote a short note for the new colleague.
Si Beatriz is the actor pivot. Ng maikling tala is the non-pivot product of the writing, and para sa bagong kasamahan expresses the beneficiary. English word order does not determine these markers; actor voice does.
Umakyat ang tekniko sa bubong para tingnan ang antena.
The technician climbed onto the roof to inspect the antenna.
Here the verb is intransitive in its central use. The mover ang tekniko is the pivot, and the goal sa bubong is an oblique phrase. -Um- therefore occurs with both one-participant motion events and events that also have a patient or product.
One family, several aspect forms
The visible -um- belongs to a paradigm, not to an English tense. For many consonant-initial roots, the basic/infinitive and completed forms contain the infix, the incompleted form combines the infix with reduplication, and the contemplated form uses reduplication without -um-.
| Root | Basic | Completed | Incompleted | Contemplated |
|---|---|---|---|---|
| bili | bumili | bumili | bumibili | bibili |
| takbo | tumakbo | tumakbo | tumatakbo | tatakbo |
| alis | umalis | umalis | umaalis | aalis |
Bumili si Niko ng gamot pagkatapos ng trabaho.
Niko bought medicine after work.
Bumibili si Niko ng gamot para sa ama niya buwan-buwan.
Niko buys medicine for his father every month.
Bibili si Niko ng gamot bago magsara ang botika.
Niko will buy medicine before the pharmacy closes.
This controlled set keeps the root bili, actor voice, and participant marking stable. What changes is the event view: complete, habitual, or not yet begun. The English translations change tense, but Filipino changes aspect.
Actor voice is an alignment, not “an active verb”
An -um- verb selects the actor-like participant as pivot. With a named actor, use si; with a common-noun actor, use ang. A core thing bought, eaten, written, or made is normally a non-pivot ng phrase.
Kumain ang mga drayber ng mainit na almusal bago bumiyahe.
The drivers ate a hot breakfast before traveling.
The plural marker is mga, and ng mainit na almusal is the patient of actor-voice kumain. The adjective and noun are connected by linker na because mainit ends in a consonant.
Now compare actor and patient voice from the same root:
Bumili si Lani ng telang iyon para sa kurtina.
Lani bought that fabric for the curtain.
Binili ni Lani ang telang iyon para sa kurtina.
Lani bought that fabric for the curtain.
Ng telang iyon can be fully specific; ng is not simply the English article “a.” In the second clause, patient-voice binili selects the fabric as ang pivot and changes the actor marker to ni. This page identifies the structural contrast, while discourse-conditioned choice between voices belongs to the dedicated voice guides.
Lexical distribution has to be learned
The root is a family of constructions, not a single English-style verb stem. One citation form hides that derivational system. Sagot supports sumagot “respond” and magsagot “answer items/questions,” but those actor-voice forms are not freely interchangeable. Akyat gives intransitive umakyat “go/climb up,” while mag-akyat commonly introduces something carried or moved upward.
Umakyat si Paolo sa ikalawang palapag para kunin ang payong niya.
Paolo went up to the second floor to get his umbrella.
Nag-akyat si Paolo ng dalawang kahon sa ikalawang palapag.
Paolo carried two boxes up to the second floor.
The affix contrast here changes valency and lexical construal, not merely style. There is no universal rule that -um- means “simple action” and mag- means “deliberate action.” Some borrowed or variable families, such as bumiyahe/magbiyahe, show more than one contemporary pattern, with preferences depending on speaker and collocation. Treat accepted alternatives as lexical facts, not as permission to alternate every root.
Questions, negatives, and a short exchange
Question and negative words do not replace the verb's voice or aspect.
Hindi umalis si Dina dahil hinihintay pa niya ang tawag ng doktor.
Dina did not leave because she was still waiting for the doctor's call.
—Sino ang sumulat ng paalala sa pisara? —Sumulat si Gino bago magsimula ang klase.
—Who wrote the reminder on the board? —Gino wrote it before class began.
Completed umalis and sumulat retain actor voice under negation and questioning. In the exchange, the unknown actor is queried with sino, and the answer supplies actor pivot si Gino.
Common Mistakes
Inventing an -um- form for every English verb
❌ Lumuto si Rina ng lugaw para sa maysakit.
Incorrect in neutral standard Filipino — luto belongs to the ordinary mag- actor-voice family, not an invented -um- family.
✅ Nagluto si Rina ng lugaw para sa maysakit.
Rina cooked rice porridge for the sick person.
The correction changes the affix family, not just spelling. Lexical membership must be learned.
Placing the infix after the first vowel
❌ Suumlat si Nico ng mensahe bago umalis.
Incorrect — -um- goes before the first vowel of consonant-initial sulat.
✅ Sumulat si Nico ng mensahe bago umalis.
Nico wrote a message before leaving.
The established surface form is sumulat, written as one word.
Adding an English tense ending
❌ Bumilied si Tess ng bagong kandado kahapon.
Incorrect — Filipino does not add English -ed to completed bumili.
✅ Bumili si Tess ng bagong kandado kahapon.
Tess bought a new padlock yesterday.
Completed aspect is already expressed by the Filipino paradigm; kahapon supplies the past-time frame.
Combining actor voice with a patient pivot
❌ Bumili si Dina ang ekstrang susi kahapon.
Incorrect — actor-voice bumili requires its core patient as a non-pivot ng phrase.
✅ Bumili si Dina ng ekstrang susi kahapon.
Dina bought an extra key yesterday.
If the key is to be the pivot, the construction must change as a whole: Binili ni Dina ang ekstrang susi kahapon.
Key Takeaways
- -Um- marks an established actor-voice family; it is an infix with consonant-initial roots and initial um- with vowel-initial roots.
- Actor voice selects the actor as ang/si pivot; other participants follow the verb's lexical frame.
- -Um- participates in an aspect paradigm: bumili, bumibili, bibili.
- A root is a family of constructions, and its dictionary form does not reveal every permitted affix, meaning, or valency pattern.
- Learn accepted forms from usage; do not attach -um- or English tense endings mechanically.
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Start learning Filipino →Related Topics
- 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.
- Verb Paradigms as Aspect-and-Voice FamiliesA2 — Read Filipino verb paradigms as intersecting choices of event aspect and participant voice rather than as English tense conjugations.
- Infinitive and Contemplated FormsA2 — Distinguish aspect-neutral infinitive or basic verb forms from contemplated forms that present an event as not yet begun.
- 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.
- Actor VoiceB1 — Use actor voice to select an actor, experiencer, or moving participant as pivot while marking patients and obliques appropriately.
- The -um- actor voice: Valency, Voice, and Lexical RestrictionsB1 — Understand which participants -um- verbs license, how actor voice marks them, and why affix choice remains lexical.