The tahu family separates ordinary possession of knowledge from formal epistemic framing and the discovery of something hidden. Bare tahu is the everyday predicate in tahu jawabannya and tahu bahwa.... Mengetahui and diketahui package the knower or known information more explicitly, especially in careful prose. Ketahuan does something different: a secret, offense, or culprit becomes known—often because someone is caught.
The family also contains the lexical noun pengetahuan. These established meanings cannot be predicted by attaching an English gloss to each affix. This page concentrates on their valency and usage; general meN-...-i, di-...-i, and ke-...-an formation belongs on the Word Formation and Voice pages.
No person or tense paradigm
Tahu is an invariant stative predicate, not an infinitive corresponding to English to know. Its form does not change with the subject or time.
| Frame | Indonesian | What supplies the interpretation |
|---|---|---|
| first person | Saya tahu jawabannya. | saya; no agreement ending |
| third person | Dia tahu jawabannya. | dia; same predicate |
| plural | Mereka tahu jawabannya. | mereka; same predicate |
| past state | Dulu saya sudah tahu. | dulu and sudah |
| current gap | Sekarang kami belum tahu. | sekarang and belum |
| future acquisition | Besok kita akan tahu. | besok and akan |
Saya tahu jawabannya, tetapi ingin mendengar pendapatmu.
I know the answer, but I want to hear your opinion.
Dulu mereka tidak tahu jalan menuju desa itu.
They did not know the way to that village before.
Besok kita akan tahu apakah permohonan itu diterima.
Tomorrow we will know whether the application was accepted.
Indonesian never adds equivalents of English knows or knew. Sudah, belum, and akan remain separate. Because knowing is normally a state rather than an unfolding activity, neutral sedang tahu is also unnatural.
Tahu: everyday knowledge
Bare tahu can take a noun phrase, a content clause, an embedded question, or a topic phrase. It is neutral across everyday conversation and much ordinary writing.
Kamu tahu alamat kantor barunya?
Do you know the address of the new office?
Saya tahu bahwa rapatnya dipindahkan ke hari Jumat.
I know that the meeting was moved to Friday.
Tidak ada yang tahu mengapa listrik tiba-tiba padam.
Nobody knows why the power suddenly went out.
Dia tahu cara memperbaiki mesin itu tanpa membuka seluruh penutupnya.
He/She knows how to repair that machine without removing the entire cover.
Saya hanya tahu sedikit tentang sejarah daerah ini.
I know only a little about the history of this region.
Tahu + noun expresses knowledge of a fact, answer, name, route, or method. Tahu tentang + topic means know about a subject. Tahu bahwa + clause introduces propositional content. English uses the same verb for knowing a fact and knowing a person; Indonesian normally uses kenal/mengenal, treated in the kenal family guide, for personal acquaintance.
Saya tahu namanya, tetapi belum pernah bertemu dengannya.
I know his/her name, but I have never met him/her.
Saya tidak kenal orangnya meskipun tahu namanya.
I do not know the person even though I know the name.
Aspect and change of knowledge
Since tahu is stative, Indonesian uses particles to describe whether the knowledge already holds or has not yet been acquired. Baru tahu often means “have just found out,” so baru can shift attention from the resulting state to its recent onset.
Saya sudah tahu hasilnya sejak tadi pagi.
I have known the result since this morning.
Kami belum tahu kapan jalan itu akan dibuka kembali.
We do not yet know when that road will reopen.
Saya baru tahu kalau Rina pindah ke Makassar.
I just found out that Rina moved to Makassar. (everyday)
In careful writing, bahwa is the neutral clause introducer. Content kalau is very common in conversation (informal). Neither changes the valency of tahu.
Mengetahui: explicit and careful epistemic framing
Mengetahui is an established meN-...-i verb, not merely a decorated synonym selected whenever the subject is an actor. It is common in reports, procedures, academic prose, and careful narration (formal). It can mean know, learn, become aware of, or establish through observation.
Tim teknis mengetahui sumber gangguan setelah memeriksa kabel utama.
The technical team identified the source of the disruption after inspecting the main cable. (formal)
Kami ingin mengetahui alasan perubahan jadwal tersebut.
We want to know the reason for that schedule change. (formal)
Setelah mengetahui bahwa datanya keliru, peneliti mengulang analisis.
After learning that the data was incorrect, the researcher repeated the analysis. (formal)
Orang tua berhak mengetahui perkembangan kondisi anaknya.
Parents have the right to know how their child's condition is developing. (formal)
The object normally follows directly: mengetahui alasan, mengetahui hasil, mengetahui perkembangan. Mengetahui tentang masalah itu occurs, but mengetahui masalah itu or tahu tentang masalah itu is usually more economical, depending on whether careful framing or an everyday topic relation is intended.
Like tahu, stative mengetahui generally resists progressive sedang. Use mulai mengetahui when a gradual acquisition of information is intended.
Sedikit demi sedikit, warga mulai mengetahui dampak perubahan aturan itu.
Little by little, residents are beginning to understand the impact of the rule change.
Diketahui: known, established, or reported
Diketahui centers the fact, cause, identity, or other information that is known. It is frequent in impersonal formal statements because the knower may be obvious, collective, or irrelevant.
Belum diketahui penyebab kebakaran di gudang tersebut.
The cause of the fire in that warehouse is not yet known. (formal)
Dari rekaman kamera, diketahui bahwa kendaraan itu datang dari arah selatan.
From the camera footage, it was established that the vehicle came from the south. (formal)
Identitas pemilik tas sudah diketahui petugas.
The owner of the bag has already been identified by the officers.
Sejauh yang diketahui peneliti, spesies itu hanya hidup di pulau tersebut.
As far as the researchers know, that species lives only on that island. (academic)
The high-frequency frame diketahui bahwa + clause presents a proposition as established without centering one investigator. Passive di- is attached: diketahui. Locative di laboratorium remains separate.
Ketahuan: discovery, exposure, and being caught
Ketahuan presents a hidden fact, action, or participant as becoming known. With a human subject plus an action complement, it commonly means “be caught doing...” With a secret or deception as subject, it means “come out/be discovered.” It is standard, though the “caught in the act” use is especially frequent in conversation.
Akhirnya ketahuan siapa yang mengganti jadwal tanpa izin.
It finally came out who had changed the schedule without permission.
Mereka ketahuan masuk melalui jendela belakang.
They were caught entering through the back window.
Kebohongannya ketahuan setelah kedua laporan dibandingkan.
The lie was uncovered after the two reports were compared.
Jangan menyalin jawaban teman; nanti ketahuan guru.
Do not copy your friend's answers; the teacher will catch you. (informal)
Ketahuan is not the ordinary passive of tahu. Penyebabnya diketahui neutrally says the cause is known; kecurangannya ketahuan evokes something concealed being exposed. A formal report may replace conversational ketahuan mencuri with tertangkap sedang mencuri or another precise event description.
Pengetahuan and useful lexical expressions
Pengetahuan is a noun meaning knowledge, expertise, or what is known about a domain. It takes modifiers and topic phrases, not a direct verbal object.
Pengetahuan dasar tentang pertolongan pertama sangat berguna.
Basic knowledge of first aid is very useful.
Pelatihan itu menambah pengetahuan peserta tentang keamanan data.
The training increases participants' knowledge of data security.
Keputusan tersebut dibuat berdasarkan pengetahuan yang tersedia saat itu.
The decision was made on the basis of the knowledge available at the time. (formal)
Several common expressions must be learned whole. Cari tahu means investigate or find out, memberi tahu means tell/inform, and ingin tahu expresses curiosity. The noun tahu “tofu” is an unrelated homonym; context distinguishes Saya tahu jawabannya from Saya membeli tahu.
Saya akan mencari tahu siapa yang bertugas malam ini.
I will find out who is on duty tonight.
Tolong beri tahu saya kalau paketnya sudah tiba.
Please tell me when the package has arrived.
Anak itu selalu ingin tahu cara kerja setiap alat.
That child is always curious about how every tool works.
Common Mistakes
1. Using tahu for personal acquaintance
❌ Saya tahu dokter itu sejak kecil.
Incorrect for personal acquaintance — tahu normally concerns information.
✅ Saya kenal dokter itu sejak kecil.
I have known that doctor since childhood.
2. Applying progressive aspect to a knowledge state
❌ Saya sedang tahu jawaban pertanyaan terakhir.
Incorrect — stative tahu is not normally progressive.
✅ Saya sudah tahu jawaban pertanyaan terakhir.
I already know the answer to the final question.
3. Splitting passive di-
❌ Belum di ketahui kapan jembatan itu dibuka.
Incorrect spelling — passive di- attaches to ketahui.
✅ Belum diketahui kapan jembatan itu dibuka.
It is not yet known when the bridge will open.
4. Using ketahuan for neutral possession of knowledge
❌ Saya ketahuan alamat rumah barunya.
Incorrect — ketahuan describes discovery or exposure, not simply knowing a fact.
✅ Saya tahu alamat rumah barunya.
I know the address of the new house.
5. Adding an English agreement ending
❌ Dia tahus siapa yang menelepon tadi.
Incorrect — tahu never takes a third-person singular ending.
✅ Dia tahu siapa yang menelepon tadi.
He/She knows who called earlier.
Key Takeaways
- Tahu is the everyday stative predicate for facts, answers, methods, and content clauses.
- Mengetahui gives knowledge explicit actor-oriented, often formal framing; diketahui centers established information.
- Ketahuan profiles discovery, exposure, or being caught, not neutral passive knowledge.
- Pengetahuan is a lexical noun for knowledge or expertise.
- All family members are invariant for person and tense; actual derivatives are solid and aspect words remain separate.
Now practice Indonesian
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Indonesian →Related Topics
- kenal and memperkenalkan: Verb Family and UsageB1 — Distinguish acquaintance and familiarity with kenal or mengenal from reputation, recognition, and the introduction patterns of memperkenalkan.
- Bare Verbal Roots: Overview and FormationA1 — Recognize Indonesian verbal roots as complete predicates in unaffixed, imperative, conversational, serial, and object-oriented constructions.
- -i Applicative Patterns: Overview and FormationB2 — Recognize how -i stems select locations, goals, recipients, containers, and repeatedly affected targets as direct objects.
- ke-...-an Experiencer Constructions: Advanced Constraints and RegisterC2 — Handle relativization, extraction, lexical exceptions, agent suppression, and register variation in advanced ke-...-an experiencer clauses.
- belum: Not Yet and Expected ChangeA1 — Use belum when an expected event or state has not been realized by the current or contextually supplied reference time.
- baru: Just, Only Recently, and NewA2 — Use baru after a noun for newness and before predicates, quantities, or sequence points for recency, limitation, and only-then meanings.