English what does the work of two Greek words, so every question you build forces a decision English never made you make. The basic principle is settled elsewhere: in front of a noun, ποιος picks a member out of a set you both have in view and τι asks for a kind, with no set implied — the Τι κρασί προτιμάς; against Ποιο κρασί να ανοίξω; contrast, and the Ποιο είναι το όνομά σου; case, are worked out on interrogative determiners. That is the rule, and this page does not re-derive it.
What that page left over is what this one is for: the two words standing without a noun, the zone where both are genuinely available and the choice carries meaning, and the handful of frozen τι-expressions where ποιος is simply not an option.
With no noun, τι needs nothing and ποιο needs an antecedent
This is the deepest difference between them and it is easy to state. τι can start a conversation from cold. You walk into a room where something has clearly gone on and you say Τι έγινε; — no set, no context, nothing established. A bare ποιο, by contrast, is a pointer: its ending agrees with a noun, so there must be a noun, already understood by both speakers, for it to agree with.
Τι να φορέσω απόψε; Δεν έχω ιδέα τι θα φοράνε οι άλλοι.
ti na foréso apópse; dhen écho idhéa ti tha foráne i áli
What shall I wear tonight? I've no idea what everyone else will be wearing.
Ποιο να φορέσω, το μπλε ή το άσπρο;
pio na foréso, to ble i to áspro;
Which shall I wear, the blue one or the white one?
The first is asked in front of an open wardrobe, the second with two shirts already in your hands. Take the shirts away and the second question collapses — there is nothing left for ποιο to agree with, and the neuter ending points at nobody. That is why Τι έγινε;, Τι λες;, Τι θέλεις; are askable in a vacuum and their ποιο-versions are not.
Τι είπες; Δεν κατάλαβα λέξη.
ti ípes; dhen katálava léksi
What did you say? I didn't catch a word of it.
People go to ποιος, things can go either way
Standing alone, ποιος is the ordinary word for who and τι the ordinary word for what — but that is a consequence of the set rule, not an extra rule bolted on. People come to us pre-sorted into identifiable individuals: asking about a person is nearly always asking which of these humans, and that is ποιος territory by definition. Things are not always so sorted, which is why they take both words depending on the situation.
τι is not blocked from people, though; it just asks something else. It asks what category the person falls into.
Τι είναι ο πατέρας σου, γιατρός;
ti íne o patéras su, yatrós;
What does your father do — is he a doctor?
Ποιος είναι ο πατέρας σου από τους δύο;
pios íne o patéras su apó tus dhío;
Which of the two is your father?
Both are good Greek and neither is a mistake for the other. The first asks for a profession, the second for an identification out of a pair. The same logic explains why a name is asked with ποιο, worked out on interrogative determiners; the case behaviour of these standalone forms — Ποιον; against Ποιος; — is on interrogative pronouns.
The overlap zone: Τι δουλειά; against Ποια δουλειά;
Now the part where learners want a rule and there is genuinely a choice. With category nouns — δουλειά, ταινία, μουσική, φαγητό, χρώμα — both words produce a fully natural question, and what changes is what you are presupposing about your listener's answer.
Τι δουλειά κάνει η γυναίκα σου;
ti dhuliá káni i yinéka su;
What does your wife do for a living?
Ποια δουλειά σε ενδιαφέρει από τις δύο;
pia dhuliá se endhiaféri apó tis dhío;
Which of the two jobs are you interested in?
The τι-version wants a kind and presupposes nothing: any job in the world is an acceptable answer. The ποια-version presupposes that a specific short list exists and that your listener knows what is on it. Ask Ποια δουλειά κάνεις; of a stranger and it sounds as though you are expecting one of a handful of jobs you already had in mind — which is occasionally exactly what you want, and usually not.
Τι ταινία είδατε τελικά;
ti tenía ídhate teliká;
What film did you end up seeing?
Ποια ταινία είδατε, την ελληνική ή τη γαλλική;
pia tenía ídhate, tin elinikí i ti ghalikí;
Which film did you see, the Greek one or the French one?
One refinement worth having, because it is where the "closed set" formula is usually overstated: spelling the alternatives out in the question does not by itself force ποιος. What matters is whether those alternatives are definite items or indefinite kinds. Compare:
Τι θέλεις, τσάι ή καφέ;
ti thélis, tsái i kafé;
What would you like, tea or coffee?
Ποιον καφέ θέλεις, τον ελληνικό ή τον φραπέ;
pion kafé thélis, ton elinikó i ton frapé;
Which coffee do you want, the Greek one or the frappé?
Bare τσάι ή καφέ names two kinds of drink; τον ελληνικό ή τον φραπέ, with articles, names two specific things on offer. The article on the alternatives is a reliable tell.
The frozen τι-expressions
A small group of everyday questions are lexicalised: they are stored whole, and the noun inside them is not a set member being chosen from anything. Substituting ποιος does not make them more precise, it makes them wrong.
| Expression | Meaning | Register |
|---|---|---|
| Τι ώρα είναι; | What time is it? | neutral |
| Τι κάνεις; / Τι κάνετε; | How are you? | neutral; the plural is polite or to a group |
| Τι γίνεται; | What's going on? / How's things? | neutral to informal |
| Τι λέει; | What's the story? / What's up? | (informal), among friends |
| Τι να κάνουμε; | What can you do? (resignation) | neutral |
| Τι στο καλό; | What on earth? | (informal) |
Τι κάνεις; Χρόνια και ζαμάνια!
ti kánis; chrónia ke zamánia
How are you? It's been ages!
Τι λέει, ρε συ, πού χάθηκες τόσο καιρό;
ti léi, re si, pu cháthikes tóso keró;
What's the story, mate — where have you been all this time? (informal)
Τι γίνεται με το ραντεβού, το κλείσαμε τελικά;
ti yínete me to randevú, to klísame teliká;
What's happening with the appointment — did we book it in the end?
Τι κάνεις; deserves a note: read literally it is "what are you doing?", and it can still mean that with the right intonation and context, but as a greeting it is as fixed as English how are you? and just as empty of literal content. Τι λέει; works the same way — literally "what does he say?", in practice a greeting between friends.
The frozen status is worth taking seriously, because ποιος is available with the same nouns in other sentences. Τι ώρα είναι; asks what the clock says; Ποια ώρα σε βολεύει; asks you to pick an hour out of the ones on the table. Those are two different questions, and only the first is frozen.
Ποια ώρα σε βολεύει, στις έξι ή στις οκτώ;
pia óra se volévi, stis éksi i stis októ;
Which time suits you, six or eight?
Quick decision
| Situation | Word |
|---|---|
| Nothing established; you could ask this walking into a room | τι |
| Asking which person | ποιος |
| Asking what category a person or thing falls into | τι |
| The candidates are physically or conversationally present | ποιος, agreeing with them |
| Alternatives named without articles (kinds) | τι |
| Alternatives named with articles (specific items) | ποιος |
| One of the fixed expressions above | τι, no choice |
Common Mistakes
1. Switching to ποιος and forgetting that you have just taken on an agreement obligation. τι costs nothing; the moment you replace it, you must know the noun's gender.
❌ Ποιο δουλειά κάνεις τώρα;
Incorrect — δουλειά is feminine, so switching from τι to ποιος gives ποια δουλειά.
✅ Ποια δουλειά κρατάς τελικά, την πρωινή ή τη βραδινή;
pia dhuliá kratás teliká, tin proiní i ti vradhiní;
Which job are you keeping in the end, the morning one or the evening one?
2. Using a bare ποιο for an open question with nothing to point at.
❌ Ποιο έγινε στο σπίτι σου χθες;
Incorrect for an open 'what happened?' — a standalone ποιο agrees with a noun already in play, and here there is none. The question is Τι έγινε;
✅ Τι έγινε στο σπίτι σου χθες; Ακούγαμε φωνές μέχρι τις δύο.
ti éyine sto spíti su chthes; akúghame fonés méchri tis dhío
What happened at your place yesterday? We could hear shouting until two.
3. "Improving" a frozen expression. Learners who have just met the set rule reason that the hour is one item out of twelve, and repair a question that was never broken.
❌ Ποια ώρα είναι, μήπως ξέρεις;
Incorrect for asking the clock time — that question is stored whole as Τι ώρα είναι;
✅ Τι ώρα είναι; Το κινητό μου κλείδωσε και δεν το ανοίγω.
ti óra íne; to kinitó mu klídhose ke dhen to anígho
What time is it? My phone's locked and I can't get into it.
4. Picking the wrong frozen greeting for the person in front of you. All of these are τι-expressions and all are correct Greek; what separates them is who you are talking to, and getting that wrong is the most audible slip on this page.
Τι λέει, Γιώργο; Θα κατέβεις για καφέ;
ti léi, Yórgho; tha katévis ya kafé;
What's up, Yorgo? Coming down for a coffee? (informal — friends only)
Τι κάνετε, κύριε Παπαδόπουλε; Χαίρομαι που σας βλέπω.
ti kánete, kírie Papadhópule; chérome pu sas vlépo
How are you, Mr Papadopoulos? Good to see you. (polite — the plural form to one person)
Key Takeaways
- τι needs no antecedent; a bare ποιο does. Τι έγινε; can be asked from cold; Ποιο; only works when a noun is already understood by both speakers.
- Standing alone, ποιος = who and τι = what, but that falls out of the set rule: people are always an identifiable set.
- τι with a person asks a category (Τι είναι ο πατέρας σου; = what does he do), which is a real question, not a broken version of ποιος.
- In the overlap zone — δουλειά, ταινία, μουσική — both are correct: τι presupposes nothing, ποιος presupposes a short list your listener knows.
- Listing alternatives does not force ποιος; articles on the alternatives do. τσάι ή καφέ → τι; τον ελληνικό ή τον φραπέ → ποιον.
- The frozen expressions — Τι ώρα είναι;, Τι κάνεις;, Τι γίνεται;, Τι λέει; (informal), Τι να κάνουμε; — take τι and only τι. But Ποια ώρα σε βολεύει; is a different, perfectly good question.
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Start learning Greek →Related Topics
- Interrogative PronounsA2 — When a Greek question word stands with no noun after it, it becomes a pronoun — ποιος (who / which one), τι (what) and πόσος (how many) — and ποιος still agrees with the noun you both have in mind but never said. Covers the standalone forms, why case alone separates Ποιος πήρε τη Μαρία; from Ποιον πήρε η Μαρία;, and the case a one-word answer comes back in.
- Interrogative Determiners: ποιος, πόσος, τιA2 — Three question words attach directly to a noun in Greek — ποιος (which, from a known set), πόσος (how much / how many) and invariable τι (what kind of) — and two of the three decline, so you must fix the noun's gender before you can even ask. This page gives both paradigms, the ποιος-versus-τι line that English blurs, and the rule English speakers break first: an interrogative determiner takes a bare noun, never the article.
- Questioning Prepositional ObjectsA2 — English lets you leave a preposition dangling at the end — who did you go with? — and Greek never does: the preposition travels to the front glued to its question word, giving Με ποιον πήγες;, Σε ποιον το έδωσες;, Από πού είσαι; Covers the fronting rule, why γιατί is literally για + τι, and the rule nobody teaches — that a one-word answer has to carry the preposition back.