Choose an established i- family when the pivot is conventionally a theme being conveyed, placed, sent, applied, worn, or put into a form—or, with some verbs, a beneficiary or instrument. Choose an established -in family when the pivot is a patient directly affected, created, consumed, read, or otherwise targeted. This semantic contrast is useful, but lexical convention remains decisive.
Both families normally mark the actor with ng/ni or an ng-form pronoun and the selected pivot with ang/si. English often translates either one with an ordinary transitive verb, so an English “object” cannot choose the Filipino affix. All unlabelled examples below are neutral contemporary Filipino.
The quick comparison
| Decision point | i- family | -in family |
|---|---|---|
| Frequent pivot role | conveyed/placed theme, applied item, content put into form; sometimes beneficiary or instrument | affected, created, consumed, read, chosen, or targeted patient |
| Basic examples | ibigay, ilagay, isulat, itapon, isuot, ibili | basahin, lutuin, bilhin, kainin, sulatin |
| Typical other phrase | destination/recipient often sa/kay | location/recipient remains in the verb's lexical frame |
| Actor | ng/ni or ng-form pronoun | ng/ni or ng-form pronoun |
| Reliable rule | learn the full verb with the semantic role of its pivot | |
The prefix i- is a voice-forming element. By contrast, “the -in family” is a conventional paradigm label: its basic form may end in -in/-hin, but its completed form commonly uses internal -in-, as in basahin → binasa.
Step 1: ask whether something is being put somewhere or into a form
The i- family is natural when a selected theme moves toward a destination or is encoded on a surface.
Ilagay mo sa palamigan ang natirang sopas bago matulog.
Put the leftover soup in the refrigerator before going to bed. (i-; placed theme pivot)
Isulat ninyo sa pisara ang tatlong tanong para sa talakayan.
Write the three discussion questions on the board. (i-; content put into writing as pivot)
The pivots are ang natirang sopas and ang tatlong tanong. Their destinations remain sa palamigan and sa pisara. The actor is mo/ninyo.
An -in form instead often treats the pivot as the item being worked on:
Basahin mo ang huling talata bago sagutin ang mga tanong.
Read the last paragraph before answering the questions. (-in; reading material as patient pivot)
There is no neutral ibasahin alternative. The lexical family of basa selects basahin for this event.
Step 2: compare two families of one root
The root sulat supports both patterns, with an important tendency:
Sulatin mo ang maikling sanaysay tungkol sa iyong lola.
Write the short essay about your grandmother. (-in; composed text as patient/product pivot)
Isulat mo sa kard ang buong pangalan ng iyong lola.
Write your grandmother's full name on the card. (i-; selected content put onto a surface)
Sulatin readily construes the selected text as the product to compose. Isulat readily construes selected content as something put into written form or onto a surface. The boundary is not absolute: speakers use isulat for many kinds of writing, and context can make isulat/sulatin overlap. Learn common collocations rather than claiming a rigid English distinction.
Completed forms preserve the tendency:
Sinulat ni Mara ang sanaysay sa loob ng dalawang araw.
Mara wrote the essay in two days. (-in family; completed product)
Isinulat ni Mara sa sobre ang bagong tirahan ng kaniyang lola.
Mara wrote her grandmother's new address on the envelope. (i- family; completed transfer into writing)
Step 3: a beneficiary can be the i- pivot
Simple i- does not always select a moved thing. In ibili, it selects the beneficiary, while the purchased item remains ng-marked.
Bilhin mo ang gamot na nakasulat sa reseta.
Buy the medicine listed on the prescription. (-in; purchased item as patient pivot)
Ibili mo ng gamot ang lolo mo bago magsara ang botika.
Buy your grandfather some medicine before the pharmacy closes. (i-; beneficiary pivot)
The two commands differ in pivot. Bilhin selects ang gamot; ibili selects ang lolo mo and leaves the item as ng gamot. This contrast cannot be described as direct object versus indirect object without losing the Filipino alignment.
Step 4: accept lexical gaps and fixed families
Several very common transfer verbs require i-:
Ibigay mo kay Celso ang ekstrang susi kapag dumating siya.
Give Celso the spare key when he arrives. (i-; conveyed theme pivot)
Itapon ninyo ang mga basang karton sa tamang lalagyan.
Throw the wet cardboard into the proper container. (i-; discarded theme pivot)
Standard Filipino uses ibigay and itapon, not invented bigayin and tapunin, for these frames. Conversely, it uses kainin “eat the selected item,” not ikain, in the ordinary patient construction. Productivity does not erase lexical selection.
The dedicated i- conveyance guide catalogs its wider roles; the -in patient guide covers affected-patient paradigms.
Step 5: read the aspect morphology correctly
| Family | Basic | Completed | Incompleted | Contemplated |
|---|---|---|---|---|
| i- writing | isulat | isinulat | isinusulat | isusulat |
| -in writing | sulatin | sinulat | sinusulat | susulatin |
| i- giving | ibigay | ibinigay | ibinibigay | ibibigay |
| -in reading | basahin | binasa | binabasa | babasahin |
In ibinigay, outer i- marks the lexical voice family and inner -in- participates in completed aspect. The presence of -in- inside an i- verb does not turn it into the separate -in patient family.
Negation leaves the family intact:
Hindi itinapon ni Liza ang resibo dahil kailangan pa iyon sa pagsasauli.
Liza did not throw away the receipt because it was still needed for the return. (negative completed i- family)
Questions and connected use
—Ano ang isusulat mo sa etiketa? —Isusulat ko ang petsa, pero babasahin ko muna ang tagubilin.
—What will you write on the label? —I will write the date, but I will read the instructions first. (i- for conveyed content; -in for reading material)
The question asks for the content pivot of isusulat. The response then moves to patient-voice babasahin because the instructions are the material to be read.
Register and discourse
Both families occur across conversational and formal registers. Formal administrative prose may contain more explicit recipients and destinations, while conversation omits recoverable phrases, but register does not mechanically choose the affix. Discourse prominence helps choose among lexical alternatives only after the participant frame is valid.
Decision flow
- Identify the participant intended as pivot.
- If it is a theme conveyed, placed, applied, worn, or put into a form, check the established i- family.
- If it is directly affected, created, consumed, read, or targeted, check the established -in family.
- Check whether the lexical i- verb instead selects a beneficiary or instrument.
- Choose aspect within the family and mark actor ng/ni, pivot ang/si.
Common Mistakes
Adding i- to every English transitive verb
❌ Ibasahin mo ang paalala bago pumasok sa silid.
Incorrect standard form — the established patient family for reading is basahin.
✅ Basahin mo ang paalala bago pumasok sa silid.
Read the reminder before entering the room.
Inventing -in where Filipino requires i-
❌ Bigayin mo kay Rosa ang kopya ng iskedyul.
Incorrect standard form — the transferred-theme verb is ibigay.
✅ Ibigay mo kay Rosa ang kopya ng iskedyul.
Give Rosa a copy of the schedule.
Selecting a beneficiary when the item should be pivot
❌ Ibili mo ang gamot na nasa reseta.
Incorrect for the intended command to buy the medicine itself — ibili selects a beneficiary and requires the item as an ng phrase.
✅ Bilhin mo ang gamot na nasa reseta.
Buy the medicine on the prescription. (-in; item pivot)
Keeping the actor as pivot with completed i-
❌ Ibinigay si Cora ang sobre kay Mang Isko.
Incorrect — ibinigay selects the envelope as pivot, so Cora requires ni.
✅ Ibinigay ni Cora kay Mang Isko ang sobre bago magtanghali.
Cora gave Mang Isko the envelope before noon.
Key Takeaways
The i- family often selects something conveyed, placed, applied, or encoded, but lexical members can select a beneficiary or instrument. The -in family commonly selects a directly affected, created, consumed, or targeted patient. English objecthood does not decide between them. Learn the root's full frame, recognize aspect morphology inside each family, and use discourse prominence only after the lexical construction is secure.
Related Topics
- The i- conveyance voice: Function and DistributionB1 — Learn how i- benefactive/instrumental voice selects a conveyed, placed, applied, or lexically specified participant as the pivot.
- The -in- patient voice: Function and DistributionB1 — Understand how the -in patient-voice family selects a patient pivot and why its forms and meanings must be learned as a lexical paradigm.
- Patient VoiceB1 — Use patient voice to select an affected or delimited participant as pivot while retaining the actor as a core ng-series phrase.
- Instrumental and Conveyance VoiceB1 — Use benefactive/instrumental voice patterns to select a conveyed theme, applied content, tool, material, or means as the pivot.
- Marker Choice with Patient-Voice VerbsA1 — Choose ang, ng, and personal markers with patient-voice verbs by treating the patient as pivot and the actor as non-pivot.
- Marker Choice with Benefactive-Voice VerbsA1 — Learn how benefactive voice makes the person benefiting from an action the ang/si pivot while actor and theme take ng forms.