3.8 di-/ke- Prefix vs Preposition Distinction
Key Takeaways
- di as a preposition (place/time) is written separately: di kantor, di Jakarta, di waktu itu. di- as a passive prefix is written attached: ditulis, dibaca.
- ke as a preposition (direction) is written separately: ke kantor, ke Jakarta. ke- as an ordinal prefix is written attached: ketiga, ke-21.
- The ke-...-an circumfix marks 'to undergo' a state and is written as one word: kehilangan, kedinginan, kesakitan.
- The di- passive prefix never assimilates: di- + pukul → dipukul (not dimukul), even though meN- + pukul → memukul.
- Compound forms are written separately as preposition + adverb: di dalam, di atas, ke dalam, di antara — never as one word.
di- / ke- Prefix vs Preposition Distinction
Quick Answer: di and ke are each both a preposition (written separately) and a prefix (written attached). The preposition di indicates place or time; the preposition ke indicates direction. The prefix di- marks passive voice; the prefix ke- marks ordinals and the "to undergo" sense. UKBI tests this distinction relentlessly because the written form (separate vs attached) signals the grammatical role.
The Core Rule in One Table
| Function | Written form | Example |
|---|---|---|
| di = preposition (place) | separate (two words) | di kantor, di Jakarta, di rumah, di sekolah |
| di = preposition (time) | separate | di waktu itu, di masa lalu, di saat |
| di- = passive prefix | attached (one word) | ditulis, dibaca, dilihat, dimakan, dipelajari |
| ke = preposition (direction) | separate | ke kantor, ke Jakarta, ke sekolah, ke pasar |
| ke- = ordinal prefix | attached | ketiga, kelima, kesepuluh, ke-21 |
| ke-...-an = "to undergo" | attached (circumfix) | kehilangan, kedinginan, kesakitan, kehausan |
How to Decide: A Diagnostic Test
For any di/ke item, ask two questions:
- Is what follows a noun (place/time/direction) or a verb root?
- Noun → di / ke is a preposition → write separately.
- Verb root → di- / ke- is a prefix → write attached.
- For ke specifically: is what follows a numeral or a stative root with -an?
- Numeral → ke- is an ordinal prefix → attached: ketiga, ke-100.
- Stative root + -an meaning "to undergo" → ke-...-an is a circumfix → attached: kehilangan, kedinginan.
Worked Examples
Example 1: "Ia bekerja ___ kantor." What follows is kantor, a noun (place). So di is a preposition → di kantor (separate). Wrong: dikantor.
Example 2: "Surat itu ___ tulis oleh Ahmad." What follows is tulis, a verb root. So di- is a passive prefix → ditulis (attached). Wrong: di tulis.
Example 3: "Ia pergi ___ kantor." What follows is kantor, a noun (destination). So ke is a preposition → ke kantor (separate). Wrong: kekantor.
Example 4: "Ia adalah mahasiswa ___ tiga di kelasnya." What follows is tiga, a numeral. So ke- is an ordinal prefix → ketiga (attached). Wrong: ke tiga.
Example 5: "Ia ___ hilang dompetnya." What follows is hilang, a stative root, and the sense is "to undergo the loss of". So ke-...-an is a circumfix → kehilangan (attached). Wrong: ke hilang or kehilang (without -an).
Common Errors and Distractors
UKBI items are built around four high-frequency errors:
Error 1: Writing the preposition as one word
Salah: Ia bekerja dikantor. Benar: Ia bekerja di kantor.
The preposition di must be separate from the following noun. This error mirrors the way people speak quickly, but PUEBI requires the space.
Error 2: Writing the prefix as two words
Salah: Surat itu di tulis oleh Ahmad. Benar: Surat itu ditulis oleh Ahmad.
The passive prefix di- must attach to the verb root. The space breaks the morpheme and changes the grammatical reading.
Error 3: Confusing "ke" direction with "ke-" ordinal
Salah: Ia naik ke tiga lantai. Benar: Ia naik ke lantai tiga.
In "ke lantai tiga", ke is a preposition (direction) — separate from lantai. The numeral tiga is part of the noun phrase, not an ordinal here. Compare with Ia menempati lantai ketiga where ketiga is an ordinal modifying lantai — here ke- is a prefix, attached.
Error 4: Confusing "di" place with "di-" passive after a noun
Salah: Buku itu di baca. Benar: Buku itu dibaca.
Even when the doer is omitted (no oleh phrase), the passive prefix di- attaches. The presence of a patient subject (buku itu) signals passive voice → dibaca.
Special Cases and Tricky Pairs
"di dalam" vs "didalam"
di dalam = preposition di + adverb dalam — two separate words: Ia berada di dalam ruangan. Compare didalam (one word) which is wrong in modern PUEBI. The same rule applies to di atas, di bawah, di luar, di sini, di sana, di situ — all written separately.
"ke dalam" vs "kedalam"
ke dalam = preposition ke + adverb dalam — two separate words: Ia masuk ke dalam ruangan. Note that ke dalam is somewhat pleonastic after masuk — Ia masuk ruangan is more efficient. But if used, write ke dalam as two words.
"di antara" vs "diantara"
Always separate: di antara mereka. The same for di kemudian hari, di sekitar, di seberang.
"di" before a verb-derived noun
Some nouns look like verbs but are nouns: di perkampungan — here perkampungan is a noun (with per-...-an), so di is a preposition → separate. The test: can you substitute a non-verb noun? di kampung works → di is preposition.
"di-" before a verb-derived passive with dropped nasal
Even when the root would assimilate with meN- (e.g. pukul → memukul), the passive di- does NOT assimilate: di- + pukul → dipukul, not dimukul. This is the asymmetry between meN- and di- and is a frequent distractor.
"ke-" with ordinal numerals written in figures
ke-21, ke-100, ke-2026 — when the numeral is written in figures, the prefix ke- is attached with a hyphen: ke-21. This is the only case where a hyphen appears between a prefix and a root in Indonesian.
Five-Question Quick Check
To master this section, practice answering these five for any di/ke item:
- Is what follows a verb root? → di- / ke- is a prefix → attached.
- Is what follows a noun (place)? → di is a preposition → separate.
- Is what follows a noun (destination)? → ke is a preposition → separate.
- Is what follows a numeral? → ke- is an ordinal prefix → attached.
- Is the meaning "to undergo / experience" a state? → ke-...-an is a circumfix → attached.
These five checks, applied in order, resolve every di/ke distinction in UKBI.
Which is correctly written: 'The letter was written by Ahmad' (Surat itu ___ oleh Ahmad)?
How is the phrase 'on the third floor' (di lantai ketiga) correctly written?
Which is correctly written: 'He went to Jakarta' (Ia pergi ___ Jakarta)?