Forming the present continuous with -iyor
Turkish has one tense that covers what English splits between 'I am doing' and the broader 'I do' — the present continuous, marked by -iyor. To build it, take the verb's stem (drop the -mek or -mak infinitive ending), add a vowel from the i / ı / u / ü set chosen by vowel harmony, then -yor, then a person ending. So yapmak (to do) → stem yap- → yapıyor → yapıyorum (I am doing). The yor part never changes — only the connecting vowel and the person ending shift.
Step by step
Start with the infinitive: yapmak (to do). Drop -mak: stem is yap. The last vowel of the stem is a, so by harmony the connector vowel is ı (the unrounded back vowel). Add -yor: yapıyor. Add the person ending — for 'I' it's -um: yapıyorum. The four possible connector vowels are ı, i, u, ü, and they follow the four-way harmony rule: after a/ı use ı, after e/i use i, after o/u use u, after ö/ü use ü. So gelmek (to come) → geliyorum, konuşmak (to speak) → konuşuyorum, görmek (to see) → görüyorum.
The vowel-drop rule
If the verb stem ends in a vowel, that final vowel is dropped before -iyor, because Turkish doesn't allow two vowels in a row here. başlamak (to start) → stem başla-, drop the a, add -ıyor: başlıyor, not *başlaıyor. Same with beklemek (to wait) → bekle- → bekliyor. okumak (to read) → oku- → okuyor (the u is already a harmony match, but treat it as drop-then-add: ok- + uyor). yemek (to eat) is irregular: stem ye- drops the e but the harmony vowel comes from elsewhere → yiyor, giving yiyorum (I am eating).
The person endings
After -iyor, attach: -um for 'I' (yapıyorum), -sun for 'you' (yapıyorsun), nothing for 'he/she/it' (yapıyor), -uz for 'we' (yapıyoruz), -sunuz for 'you (pl/formal)' (yapıyorsunuz), -lar for 'they' (yapıyorlar). Note that the personal endings after -yor always use u/ü style harmony because yor has an o in it — but in practice the endings -um, -sun, -uz, -sunuz, -lar stay the same shape across all verbs. Only -lar becomes -ler if you really need it, but -lar is standard after -yor.
What it means
-iyor covers three English meanings: (1) right-now action — Şimdi yapıyorum = I'm doing it now; (2) ongoing in this period — Türkçe öğreniyorum = I'm learning Turkish (these days); (3) general habit, like English simple present — Her gün çalışıyorum = I work every day. Turkish does have a separate 'simple present' (the -(i)r form, called geniş zaman) for true generic statements, but you can lean on -iyor for almost everything in spoken Turkish.
Negative and question
Negative: insert -mi- (with harmony: mı / mi / mu / mü) before -yor. yapmıyorum (I'm not doing), gelmiyorum (I'm not coming), görmüyorum (I'm not seeing). Question: add the unstressed particle mu after -yor, written as a separate word: Yapıyor musun? (Are you doing?), Geliyor mu? (Is he coming?). The person ending hops onto the question particle in 1st person: Yapıyor muyum? (Am I doing?), Yapıyor musunuz? (Are you (pl) doing?).
