Indonesian has both an independent second-person form kau and a bound form kau-. They look alike but behave differently: independent kau is a whole pronoun, while bound kau- leans on the following word and is written with it. Compare kau tahu and kautahu.
This is not merely a difference between careful writing and texting. The spelling reflects a grammatical choice. This page explains that choice while leaving demonstratives, full relative-clause syntax, and complete voice paradigms to adjacent pages.
Three ways to say “you know”
| Form | Analysis | Typical setting |
|---|---|---|
| kamu tahu | full familiar pronoun + predicate | ordinary informal Indonesian |
| kau tahu | independent kau + predicate | literary, lyrical, or regional speech |
| kautahu | bound kau- + predicate | compact grammatical construction, especially in writing |
Kamu tahu restoran yang masih buka malam ini?
Do you know a restaurant that is still open tonight?
Kau tahu betapa sulitnya aku mengambil keputusan itu.
You know how difficult it was for me to make that decision.
Kautahu siapa yang meninggalkan pesan ini?
Do you know who left this message?
All three can refer to one familiar addressee. Kamu is the safest choice among friends and peers in broadly understood contemporary speech. Independent kau and bound kau- carry their own register and syntactic profiles; neither is simply a fashionable abbreviation of kamu.
Independent kau
Independent kau is historically related to engkau and can function as a whole pronoun rather than part of the following word. It can be contrasted, followed by a focusing phrase, or serve as the subject of a nonverbal predicate. In contemporary Standard Indonesian it is especially associated with songs, poetry, fiction, intimate address, and certain regional varieties.
Kau satu-satunya orang yang memahami alasan saya pergi.
You are the only person who understands why I left.
Kau yang memilih tempat ini, bukan aku.
You're the one who chose this place, not me.
Hanya kau yang masih percaya padaku ketika rencana itu gagal.
Only you still believed in me when that plan failed.
These uses are often literary; in widely neutral prose and conversation, kamu is more usual. Regional speech may use independent kau every day (regional: parts of Sumatra and eastern Indonesia). Its social force then comes from that local system. Outside such communities, it may sound intensely intimate, poetic, abrupt, or confrontational.
English you gives no warning about that stance. Do not transfer it mechanically to a teacher, senior colleague, or unfamiliar adult. Indonesian often prefers Bapak, Ibu, Anda, a professional title, or omission in those relationships.
Bound kau- attaches to its host
Bound kau- is a proclitic: it functions as the second-person subject or agent but cannot stand alone. EYD V writes it solid with the following word: kautahu, kaubaca, kaupilih, kausimpan. There is no hyphen.
Pesan yang kaubaca tadi pagi berasal dari ketua panitia.
The message you read this morning came from the committee chair.
Kausimpan kuncinya di mana?
Where did you put the key?
Usul itu sudah kaupertimbangkan dengan matang.
You have considered that proposal carefully.
In pesan yang kaubaca, the message is foregrounded and kau- identifies the reader immediately before the bare verb baca. This construction interacts with Indonesian voice and relative clauses, but the spelling fact is available without learning the whole paradigm: once kau- is the bound grammatical element, attach it.
The form can also begin an independent clause, as Kausimpan kuncinya di mana? shows. Initial position does not turn it into a free word. Conversely, not every occurrence of the letters kau before another word is a proclitic: Kau yang memilih and Kau sahabatku contain a free pronoun.
Why both kau tahu and kautahu exist
With a word such as tahu, either analysis can be available. The writer may select independent kau as the subject, producing kau tahu, or compact bound kau-, producing kautahu. The difference can be subtle in meaning but remains real in grammar and orthography.
Free kau is easier to emphasize or contrast:
Kau tahu jawabannya, tetapi dia belum tahu.
You know the answer, but she doesn't know yet.
Bound kau- forms a tighter unit with the predicate and normally carries less independent emphasis:
Kautahu jawabannya sejak awal, jadi mengapa kau diam?
You knew the answer from the beginning, so why did you stay silent?
There is no universal English punctuation trick that chooses between them. The honest difficulty is syntactic: a writer must decide which pronoun construction is intended. In ordinary conversation, kamu tahu avoids this literary and clitic contrast altogether.
Kau in lyrics
Songs exploit independent kau because it is short, intimate, and rhythmically strong. They also exploit bound kau- to compress a predicate. The following original lyric deliberately places both side by side:
Kau tahu aku menunggu; kautahu jalan pulang ke hatiku.
You know that I am waiting; you know the way back to my heart. (lyrical)
This is literary/lyrical, not a model for speaking to every acquaintance. A song’s emotional directness can make kau tender in one context and accusatory in another.
Related bound spellings
The same EYD V principle attaches ku- and kau- to what follows, and -ku, -mu, and -nya to what precedes: kubaca, kaubaca, bukuku, bukumu, bukunya. The form Anda always begins with a capital letter. Titles are capitalized in direct address or name-like respectful reference where EYD V prescribes, not whenever the underlying noun appears.
Bukumu sudah kubawa, tetapi catatan yang kauminta masih ada di meja.
I've brought your book, but the notes you requested are still on the table.
See subject proclitics for the full ku-/kau- system and its interaction with voice.
Common Mistakes
1. Spacing a bound agent in a foregrounded-object construction
❌ Pesan itu kau baca tadi pagi.
Incorrect spelling for the intended bound kau- construction.
✅ Pesan itu kaubaca tadi pagi.
You read that message this morning.
2. Attaching an independent pronoun to a focusing word
❌ Kauyang harus menjelaskan keputusan ini.
Incorrect — kau is a complete pronoun before the focusing construction yang.
✅ Kau yang harus menjelaskan keputusan ini.
You're the one who has to explain this decision.
3. Adding a hyphen to the proclitic
❌ Surat yang kau-tulis sudah saya terima.
Incorrect spelling — bound kau- attaches without a hyphen.
✅ Surat yang kautulis sudah saya terima.
I have received the letter you wrote.
4. Using intimate kau upward without an established norm
❌ Kau sudah membaca laporan saya, Pak Direktur?
Inappropriately intimate or confrontational toward a senior director in this workplace context.
✅ Apakah Bapak sudah membaca laporan saya?
Have you read my report, sir?
Key Takeaways
- Kamu tahu uses the ordinary familiar full pronoun.
- Kau tahu contains independent kau, common in literature, lyrics, intimacy, and some regions.
- Kautahu contains grammatical bound kau- and is written solid.
- Bound kau- is not texting shorthand; it is a proclitic with its own syntax.
- Attach ku-, kau-, -ku, -mu, and -nya; always capitalize Anda.
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Start learning Indonesian →Related Topics
- kamu and Second-Person FamiliarityA1 — Use kamu with familiar peers and younger people while choosing titles, names, or omission when a relationship requires more distance.
- Subject Proclitics ku- and kau-B1 — Use attached ku- and kau- as first- and second-person actors in compact object-focused clauses.
- Object and Possessive -ku, -mu, and -nyaA2 — Attach -ku, -mu, and -nya to nouns, verbs, and prepositions while recovering their relation from the host and context.
- Choosing I and You: A Social Decision TreeB1 — Choose Indonesian first- and second-person reference by relationship, setting, local practice, and medium rather than formality alone.
- Writing -ku, -mu, -nya, ku-, and kau-A2 — Attach Indonesian bound pronouns on the side selected by their syntactic role and place punctuation outside the complete word.
- Age, Rank, and Institutional HierarchyB2 — Encode Indonesian institutional relationships through person reference, titles, self-positioning, collective kami, and direction-sensitive requests and directives.