Turkish glues case and possessive suffixes straight onto nouns, so ev "house" becomes evde "at home" with no visible seam. But when the noun is a proper name or an acronym, the seam becomes visible: you write an apostrophe before the suffix (Ankara'da "in Ankara," Ahmet'in "Ahmet's"). And there is a second, sneakier rule that English speakers miss: the vowel harmony of the suffix follows how the word is pronounced, not how it is spelled. This page covers both, on place names, personal names, and the two kinds of acronym.
Place names and personal names: apostrophe before the suffix
For proper nouns — people, places, organisations, titles of works — put an apostrophe between the name and any inflectional suffix (case, possessive, plural). The apostrophe keeps the capitalised name visually intact so the reader can find the base name at a glance.
Yarın sabah Ankara'dan İzmir'e uçuyorum, görüşmek üzere.
Tomorrow morning I'm flying from Ankara to İzmir; see you soon.
Ahmet'in arabası tamirde, o yüzden bizimkiyle gideceğiz.
Ahmet's car is at the garage, so we'll go in ours.
Orhan Pamuk'u lisede okumuştum, şimdi yeniden okuyorum.
I read Orhan Pamuk in high school; now I'm reading him again.
The base name keeps its own harmony rules. Note Ankara'dan uses back-vowel harmony (-dan, -a) because Ankara ends in back a, while İzmir'e uses front harmony (-e) because İzmir ends in front i.
The exception that surprises learners: derivational -lI takes no apostrophe
When a suffix derives a new word rather than inflecting the name — most famously -lI "from / belonging to / characterised by" — you write it without an apostrophe, and you lowercase nothing but the suffix simply joins on. The classic case: a person from İstanbul is an İstanbullu, written solid.
İstanbullu olduğunu konuşmasından hemen anladım.
I could tell right away from her speech that she was from İstanbul.
Ankaralı arkadaşlarım bu kışın çok sert geçtiğini söylüyor.
My friends from Ankara say this winter has been very harsh.
So you write Ankara'da (inflectional locative, apostrophe) but Ankaralı (derivational, no apostrophe). The same name, two different rules, decided by whether the suffix bends the word or builds a new one.
Acronyms: harmony follows the spoken form, not the letters
This is the heart of the page. Acronyms also take the apostrophe — but their vowel harmony is governed by how you say the acronym out loud, and Turkish has two ways of saying acronyms:
- Spelled out letter by letter (initialisms): each letter is pronounced with its Turkish letter-name. AB is said a-be, TBMM is said te-be-me-me, THY is said te-he-ye.
- Read as a word (true acronyms): NATO is said nato, TÜİK is said tüik, ASELSAN is said aselsan.
You harmonize to the last sound you actually pronounce.
Letter-by-letter acronyms
The final element is a letter-name, and you harmonize to that sound. AB ends in the spoken -e of be, so it takes front harmony: AB'ye "to the EU." TBMM ends in spoken me (front e): TBMM'nin "of the Grand National Assembly." THY ends in ye (front e): THY'nin "of Turkish Airlines."
Türkiye'nin AB'ye üyelik süreci uzun yıllardır devam ediyor.
Turkey's accession process to the EU has been going on for many years.
Kanun teklifi TBMM'nin gündemine bu hafta geliyor.
The bill is coming onto the agenda of the Grand National Assembly this week.
Bilet fiyatları yüzünden THY'yi arayıp değişiklik talep ettim.
Because of the ticket prices I called Turkish Airlines and requested a change.
Word-read acronyms
Here you harmonize to the acronym as spoken like an ordinary word. NATO is nato, ending in back o, so it takes back harmony — NATO'da "in NATO," not NATO'de, even though the letter O might tempt you. TÜİK is tüik, ending in front i, so TÜİK'in "of the Statistics Institute."
Bu konu yarın NATO'da resmî olarak görüşülecek.
This matter will be officially discussed at NATO tomorrow.
Enflasyon rakamları TÜİK'in internet sitesinde açıklandı.
The inflation figures were announced on the Statistics Institute's website.
Foreign brand names: say it the Turkish way
The same "pronounced sound" rule applies to foreign brand names and abbreviations. BMW is commonly said be-em-ve in Turkish, ending in spoken -e, hence BMW'yi with front harmony and the buffer -y- after the vowel sound.
Komşumuz geçen hafta yeni bir BMW'yi peşin almış.
Our neighbour bought a new BMW outright last week.
| Acronym | How it's said | Final sound | Harmony | Inflected |
|---|---|---|---|---|
| AB | a-be | -e (front) | front | AB'ye |
| TBMM | te-be-me-me | -e (front) | front | TBMM'nin |
| THY | te-he-ye | -e (front) | front | THY'nin |
| NATO | nato | -o (back) | back | NATO'da |
| TÜİK | tüik | -i (front) | front | TÜİK'in |
| BMW | be-em-ve | -e (front) | front | BMW'yi |
Common mistakes
❌ NATO'de önemli bir karar alındı.
NATO is said 'nato', ending in back o, so it takes back harmony: NATO'da.
✅ NATO'da önemli bir karar alındı.
An important decision was taken at NATO.
❌ Ankarada üç yıl yaşadım.
A proper noun needs an apostrophe before an inflectional suffix: Ankara'da.
✅ Ankara'da üç yıl yaşadım.
I lived in Ankara for three years.
❌ İstanbul'lu bir aileyiz, hepimiz orada doğduk.
The derivational -lI takes no apostrophe: İstanbullu, written solid.
✅ İstanbullu bir aileyiz, hepimiz orada doğduk.
We're a family from İstanbul; we were all born there.
❌ AB'ya katılım müzakereleri sürüyor.
AB is said 'a-be', ending in front e, so the dative is front: AB'ye.
✅ AB'ye katılım müzakereleri sürüyor.
EU accession negotiations are continuing.
❌ Ahmetin telefonu kapalı, ulaşamıyorum.
Personal names take the apostrophe before the genitive: Ahmet'in.
✅ Ahmet'in telefonu kapalı, ulaşamıyorum.
Ahmet's phone is off; I can't reach him.
Key takeaways
- Put an apostrophe before inflectional suffixes on proper nouns and acronyms: Ankara'da, Ahmet'in, TBMM'nin, BMW'yi.
- Derivational -lI takes no apostrophe: İstanbullu, Ankaralı — written solid, because they build a new word.
- For acronyms, harmony follows the pronounced final sound: letter-by-letter forms harmonize to the last letter-name (AB'ye, THY'nin), word-read forms to the spoken word (NATO'da back, TÜİK'in front).
- Say the acronym aloud and listen to the last voiced vowel — ignore a misleading final letter like the O in NATO.
Now practice Turkish
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Start learning Turkish→Related Topics
- The Apostrophe on Proper NounsA2 — How inflectional suffixes attach to proper nouns with an apostrophe, and why derivational suffixes never take one.
- Cases on Disharmonic and Foreign StemsB2 — Why case suffixes on loanwords, abbreviations and proper nouns follow how a word is pronounced, not how it is spelled — kalpten, otobüste, saate, NATO'da.
- Exceptions and Disharmonic WordsB1 — Why some stems break vowel harmony internally and a few suffixes opt out entirely — and why these 'exceptions' never actually break the rule for the suffixes you add.
- The Six Cases: OverviewA1 — A map of the Turkish case system — six harmonising suffixes that do the work English splits between prepositions and word order, all in one fixed slot after plural and possessive.