i/ı and Capitalization Errors | Turkish Grammar

In English, i and I are the lowercase and uppercase of a single letter, and there is nothing else in the neighbourhood. Turkish has four letters living in that space, arranged as two completely separate pairs: the dotted i / İ and the dotless ı / I. Treat them as one letter — as nearly every beginner does, and as nearly every phone autocorrect does — and you will mangle spellings, break vowel harmony, and occasionally write a different word than you meant. This page is about the three ways that goes wrong.

The single most important fact: the dot stays with the letter through case changes. Lowercase dotted i capitalises to İ (dotted capital). Capital dotless I lowercases to ı (dotless small). The dot is not decoration; it is the identity of the letter.

Lowercase	Uppercase	Name	Sound
i	İ	dotted i	"ee" as in see
ı	I	dotless ı	"uh" as in roses / the second vowel of nation

Error 1: Writing i for ı (or ı for i) in a stem

The two vowels are different sounds, so swapping them inside a word produces a misspelling — and sometimes a real but wrong word. ışık ("light") is not isik; kız ("girl/daughter") is not kiz; balık ("fish") is not balik.

❌ Odanın isigi çok parlak.

Incorrect — 'light' is ışık with two dotless ı; *isik is not the word.

✅ Odanın ışığı çok parlak.

The light in the room is very bright.

❌ Komşunun kizi liseye başladı.

Incorrect — 'daughter/girl' is kız with dotless ı, not kiz.

✅ Komşunun kızı liseye başladı.

The neighbour's daughter started high school.

The reverse error is just as common — writing dotless ı where the word has dotted i. bir ("one") is not bır; gibi ("like") is not gıbı.

❌ Onu bır kardeş gıbı seviyorum.

Incorrect — both bir and gibi have dotted i; *bır and *gıbı are wrong.

✅ Onu bir kardeş gibi seviyorum.

I love him like a brother.

Error 2: Mis-capitalising İstanbul

This is the famous one, and it is overwhelmingly an autocorrect problem. The city is İstanbul — capital dotted İ, because the lowercase letter is dotted i. An English keyboard and an English spell-checker have no dotted capital; they offer only plain I, so they silently "fix" İstanbul to Istanbul. To a Turkish reader, capital I is the uppercase of dotless ı, so Istanbul literally tells them to read the first vowel as "uh" — a jarring mistake on the name of the country's largest city.

❌ Istanbul'da üç gün kaldık.

Incorrect — the city begins with dotted İ; plain capital I is the uppercase of dotless ı and misreads the name.

✅ İstanbul'da üç gün kaldık.

We stayed in Istanbul for three days.

The same logic governs İzmir (İ, not I) and the all-caps trap, where shouting a word must preserve the dots: ÇIKIŞ ("exit", all dotless) versus İSTİKLAL (dotted İ). When you uppercase a word, dotted i must become İ, never plain I.

❌ ISTANBUL EXPRESS

Incorrect — all-caps İstanbul keeps its dot on the capital: İSTANBUL.

✅ İSTANBUL EXPRESS

ISTANBUL EXPRESS (sign / headline style).

Note also the apostrophe before the suffix on proper nouns: İstanbul'da, with a straight ASCII apostrophe, not a curly one. That is a separate convention but it shares the same headline above the word: proper names are where careful writers slow down.

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If your phone keeps turning İ into I, the fastest fix is to add a Turkish (Türkçe) keyboard. With it, the i key already types dotted İ on uppercase, and a separate key gives you ı / I. No keyboard manages the dots correctly by guesswork.

Error 3: Choosing the wrong i/ı in a suffix

This is the error that even motivated learners keep making, because it hides inside vowel harmony. Turkish suffixes with a high vowel come in a four-way set — -i, -ı, -ü, -u — and the stem's last vowel decides which one you get. If you cannot tell dotted i from dotless ı, you cannot run harmony correctly, so the spelling error and the grammar error are the same mistake.

A stem whose last vowel is a or ı takes the dotless -ı; a stem whose last vowel is e or i takes the dotted -i.

❌ Çantamda anahtari unutmuşum.

Incorrect — anahtar ends in a, so the accusative is dotless: anahtarı, not anahtari.

✅ Çantamda anahtarı unutmuşum.

I seem to have left the key in my bag.

❌ Evi temizledim, sonra çantayı topladım.

Correct as written — shown for contrast: ev ends in e, so the accusative is dotted -i (evi).

✅ Evı temizledim diye yazma; ev → evi olur.

Don't write *evı: ev takes the dotted -i because its vowel is e.

So the plural of kitap ("book") is kitaplar with a, but its accusative is kitabı with dotless ı (last stem vowel a); the accusative of ev ("house") is evi with dotted i (last stem vowel e). Get the dot wrong and you have simultaneously misspelled the word and violated harmony.

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The dotted/dotless choice in a suffix is never free. Find the last vowel of the stem: a/ı → dotless ı; e/i → dotted i; o/u → u; ö/ü → ü. The vowel you can hear tells you which letter to write.

Common mistakes

❌ Sabah erken kalktım, hava daha karanlıktı, isigi yaktım.

Incorrect — 'the light' is ışığı (dotless ı throughout the stem ışık), not isigi.

✅ Sabah erken kalktım, hava daha karanlıktı, ışığı yaktım.

I got up early, it was still dark, so I turned on the light.

❌ Yarın Izmir'e gidiyoruz, sen de gel.

Incorrect — İzmir begins with dotted İ, not plain I.

✅ Yarın İzmir'e gidiyoruz, sen de gel.

We're going to Izmir tomorrow; come along too.

❌ Bu kizla tanışmak ister misin?

Incorrect — 'girl' is kız with dotless ı; *kiz is a misspelling.

✅ Bu kızla tanışmak ister misin?

Do you want to meet this girl?

❌ Arabayi servise bıraktım, akşam alırım.

Incorrect — araba ends in a, so the accusative takes dotless -ı: arabayı, not arabayi.

✅ Arabayı servise bıraktım, akşam alırım.

I dropped the car at the garage; I'll pick it up this evening.

❌ Telefonumu sessize aldim, toplantı vardı.

Incorrect — al- ends in a, so the past suffix has dotless ı: aldım, not aldim.

✅ Telefonumu sessize aldım, toplantı vardı.

I put my phone on silent; I had a meeting.

Key takeaways

Four letters, two pairs. Dotted i / İ and dotless ı / I are not case variants of each other. The dot is the letter's identity and survives every case change.
The İ → I autocorrect trap is the number-one error. English software has no dotted capital, so it quietly destroys İstanbul, İzmir, and every uppercase dotted-i word. Install a Turkish keyboard rather than fighting it letter by letter.
Suffix vowels follow harmony, so a dot error is also a grammar error. a/ı → dotless ı, e/i → dotted i. Reading the stem's last vowel tells you which to write.
Watch the signature wrong forms: *isik for ışık, *kiz for kız, Istanbul for İstanbul, and *anahtari for anahtarı.

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