Ang, Ng, Sa: The 3 Tagalog Case Markers Explained

In English, word order tells you who did what to whom. Tagalog does that job differently. Three tiny words — ang, ng, and sa — sit in front of each noun and quietly label its role. Once you can tag every noun with the right marker, a surprising amount of Tagalog grammar stops feeling random and starts feeling like a pattern.

What Tagalog Case Markers Actually Do

Tagalog is verb-initial, so the verb usually comes first in the sentence. Because word order is flexible after that, Tagalog uses markers — not position — to tell you which noun is the subject, which is the object, and which is the location. Every common noun takes exactly one of ang, ng, or sa. Personal names use a parallel set: si, ni, kay. Plurals either add mga after the common-noun marker or switch to the plural name forms sina, nina, kina.

Mental model: the marker is the noun’s job sticker. Ang is centre-stage. Ng is a supporting role. Sa is a place, direction, or recipient.

Ang — The Topic Marker

Ang flags the noun the sentence is about. Think of it as a spotlight; whoever it lands on is the topic. It roughly corresponds to English “the,” but carries grammatical weight on top.

Tagalog	English
Kumain ang bata.	The child ate.
Maganda ang bahay.	The house is beautiful.
Kumakanta ang bata.	The child is singing.

Ang is doing two things at once here: marking the noun as specific and telling you this is the noun the sentence revolves around.

Ng — The Doer, the Possessor, the Indefinite Object

Ng is the workhorse marker, and it wears three hats: the possessor, the non-topic doer in object-focus sentences, and the indefinite object in actor-focus sentences.

Tagalog	English
Libro ng guro.	The teacher's book.
Kinain ng bata ang mansanas.	The child ate the apple.
Bumili ako ng libro.	I bought a book.

Rule of thumb: if English would use “of,” “a/an,” or “by [someone]” in a passive, Tagalog probably uses ng.

Sa — Location, Direction, Recipient

Sa is the catch-all oblique marker. It covers English “to,” “at,” “in,” “on,” “from,” and “for.” It also marks the definite recipient of a gift or action.

Tagalog	English
Pumunta siya sa palengke.	He/she went to the market.
Ibinigay ko sa bata ang regalo.	I gave the gift to the child.
Galing ako sa eskwela.	I came from school.

One thing sa is not: a possessive. Possessors always take ng or ni. Sa is spatial and directional.

Same Scene, Three Markers

This is where the system clicks. Take one cast — lalaki (man), libro (book), tindahan (store) — and watch the markers rearrange who is in the spotlight as the verb’s focus changes.

Tagalog	English
Bumili ang lalaki ng libro sa tindahan.	The man bought a book at the store.
Binili ng lalaki ang libro sa tindahan.	The man bought the book at the store.

In the first sentence, the verb is in actor focus, so ang sits on the doer (lalaki), ng marks the indefinite thing bought, and sa marks the location. In the second, the verb switches to object focus, so ang jumps to the specific book and the doer slides into ng. Same four players, different spotlight. (A third version, Binilhan ng lalaki ng libro ang tindahan, puts the store in focus using location-focus morphology — good to know it exists.)

This is the whole reason Tagalog has a verb focus system: the affix on the verb decides which role ang lands on.

Si, Ni, Kay — The Markers for People’s Names

Personal names never take ang / ng / sa. They swap in a parallel set that does exactly the same grammatical job.

Tagalog	English
Si Maria ang guro.	Maria is the teacher.
Libro ni Juan.	Juan's book.
Nagbigay ako ng bulaklak kay Ana.	I gave a flower to Ana.

Use these with first names, nicknames, and name-like address terms: si Nanay, si Kuya, si Lolo all count. Common nouns that aren’t names — guro, doktor — keep ang / ng / sa even when they refer to a specific person. When both appear together, the name wins: “si Dr. Cruz,” not “ang Dr. Cruz.” The same three-way split shows up again in the Tagalog pronoun system.

Plurals — Ang Mga, Sina, and Friends

Mga (pronounced “mah-NGAH”) is the generic plural marker. Slot it in right after the common-noun marker: ang mga, ng mga, sa mga. For names, skip mga entirely and use the dedicated plural forms sina, nina, kina.

Tagalog	English
Ang mga bata ay naglalaro.	The children are playing.
Bumili ako ng mga mansanas.	I bought some apples.
Sina Pedro at Maria ang kasama ko.	Pedro and Maria are my companions.
Pumunta ako kina Tita.	I went to Tita's place.

The full picture, laid out side by side:

Role	Common (singular)	Common (plural)	Name (singular)	Name (plural)
Topic	ang	ang mga	si	sina
Doer / possessor	ng	ng mga	ni	nina
Location / recipient	sa	sa mga	kay	kina

Ng vs Nang — Same Sound, Different Job

Ng and nang are pronounced identically — both are “nang.” Only the spelling differs. Ng is the case marker you’ve been reading about: it sits in front of a noun. Nang is an adverbial particle meaning “when” or “so that,” or it turns an adjective into an adverb. One-line rule: if you could replace it with “of,” “by,” or “a,” write ng. If it’s modifying a verb, write nang.

Tagalog	English
Bumili ako ng libro.	I bought a book. (ng — before a noun)
Kumanta siya nang malakas.	She sang loudly. (nang — adverbializer)
Natulog ako nang umuwi siya.	I slept when he came home. (nang — “when”)

Common Mistakes To Skip

Common slips: using ang for the doer in an object-focus sentence (it has to be ng there); reaching for sa to show possession; forgetting to swap to si / ni / kay with personal names; writing nang where ng belongs; stacking ang mga with a name (names use sina); and omitting the marker entirely because it felt like “just a word.” In Tagalog, the marker is the grammar.

You don’t need to master all of this today. Start by tagging every noun you meet with one of the three markers in your head — topic, doer, or place? Do that for a week, and the system will start feeling less like a rule and more like a reflex.