Tud or ismer: how do you say "to know" in Hungarian?

Use tud when you know a piece of information or know how to do something (Tudom, hol van, "I know where it is"; Tudok vezetni, "I can drive"). Use ismer when you are acquainted with a person, a place or a thing (Ismerem Pétert, "I know Péter"). The test is the object: if it is a person or a place, the answer is ismer in almost every sentence you will need.

The rule in one sentence

Hungarian splits English "know" in two, the same way German splits it into wissen and kennen, or French into savoir and connaître: tud is being aware of information, ismer is being acquainted or familiar with someone or something. If you already speak one of those languages, map tud to wissen/savoir and ismer to kennen/connaître and you will be right nearly every time.

• Tudom a választ. I know the answer. (information)
• Ismerem a tanárt. I know the teacher. (acquaintance)
• Nem tudom, ki ő. I don't know who he is. (a clause: information)
• Nem ismerem őt. I don't know him. (a person: acquaintance)

The last pair is the one to memorize. The same person can be the topic of both verbs, but "who he is" is a fact, and "him" is a person.

Decision table: pick the verb by the object

English gives you no clue, so look at what comes after "know". This table covers the object types learners actually meet.

The last two rows are the fine print most explanations skip. Tudom a verset means you can recite the poem; Ismerem a verset means you have read it and would recognize it. English "I know this song" covers both, Hungarian makes you choose: can you sing it, or have you just heard it?

Tud: facts, clauses, skills and languages

Information and clauses

The core meaning of tud is knowing a piece of information. Most often that information is a whole clause, introduced by hogy ("that") or a question word:

• Tudom, hogy igazad van. I know you are right.
• Tudja valaki, hol a kulcs? Does anyone know where the key is?
• Nem tudjuk, mit csináljunk. We don't know what to do.

A clause object always takes the definite conjugation, which is why "I know" on its own is Tudom and "I don't know" is Nem tudom: the "it" or "that" is understood. Replying *Tudok to "Do you know where it is?" is wrong.

Skills: tud + infinitive means "can"

With an infinitive, tud means "can, be able to, know how to". This covers both learned skills and practical ability in the moment:

• Tudok vezetni. I can drive. (I know how to.)
• Holnap nem tudok jönni. I can't come tomorrow. (I'm not able to.)
• Nem tudom kinyitni az ablakot. I can't open the window.

A near-synonym for this sense is the adjective képes, "able, capable": Nem képes dönteni, "He is not able to decide". In everyday speech, tud is the normal choice.

Languages

For languages, Hungarian uses tud with the language adverb in -ul/-ül, not an object: Anna tud magyarul, "Anna speaks Hungarian". Beszél magyarul means the same. Note that there is no accusative here, so the verb is indefinite: Tudok angolul, "I speak English", Tudsz németül? "Do you speak German?"

Ismer: people, places and things you are acquainted with

Ismer means you have met, visited, seen or used the thing yourself. Its objects are almost always nouns, never clauses and never infinitives.

• Régóta ismerjük egymást. We have known each other for a long time.
• Nem ismerem ezt a környéket. I don't know this area.
• Ismered ezt a szót? Do you know this word? (Have you come across it?)
• Látásból ismerem. I know him by sight.
• Hírből ismerem. I know of him (by reputation).

Compare Ismered ezt a szót? ("Have you seen this word before?") with Tudod, mit jelent ez a szó? ("Do you know what this word means?"). The first is familiarity, the second is a fact, so the verb changes even though the word is the same.

For "I know you" to a friend, ismer takes the -lak/-lek ending: Ismerlek, "I know you", and in the past Ismertelek, "I knew you". To someone you address formally, it is the ordinary definite form: Ismerem Önt (see formal and informal you).

Both verbs in both conjugations

Each verb has an indefinite and a definite form, and the choice follows the object exactly as with any other transitive verb (the rules are on the definite and indefinite conjugation page). Both are regular: tud takes back-vowel endings, ismer front-vowel ones.

Watch ismertek: in the present it is "you (pl) know", but the same spelling is also the past "they knew", from the past stem ismert-. Context decides.

Minimal pairs

Ért, megismer, felismer and ismerős

Four relatives cover the English uses of "know" that neither verb handles well.

Ért answers "Do you understand?" (Érted?), not "Do you know?". Its -hoz/-hez use (the allative case) is how Hungarian says "he knows about cars": Ért az autókhoz, never *Tudja az autókat.

Megismer is the change-of-state partner of ismer: ismer is a state ("know"), megismer is the moment you meet ("get to know"). That is why "Nice to meet you" is Örülök, hogy megismertelek, literally "I'm glad I got to know you" (the meg- prefix is explained on verbal prefixes). Felismer is recognizing someone or something you have met before, and also "realize": Felismerte a hibát, "He realized the mistake".

Ismerős is the handiest word of the family. As an adjective it means "familiar" (Ismerős nekem ez az ember, "This person looks familiar to me"; Nem vagyok ismerős ezen a környéken, "I don't know this area"). As a noun it is "an acquaintance", the everyday word for someone you know but would not call a friend.

Tud + infinitive vs -hat/-het: can or may?

Once tud means "can", learners start using it for permission too. Hungarian keeps the two apart: ability goes with tud + infinitive, permission and possibility with the -hat/-het suffix on the verb itself.

The suffix also attaches to tud itself, giving "may know": Honnan tudhatnám?, "How could I (possibly) know?"

Common learner errors

1. *Tudom Pétert. A person takes ismer: Ismerem Pétert.
2. *Ismerem, hol lakik. A clause takes tud: Tudom, hol lakik.
3. *Tudok. as "I know." The implied "it" is definite: Tudom. / Nem tudom.
4. *Ismerek úszni. Skills take tud: Tudok úszni.
5. *Tudok magyart. Languages take the adverb, not an object: Tudok magyarul.
6. *Tudom ezt a várost. A place takes ismer: Ismerem ezt a várost.
7. *Örülök, hogy ismerlek as "Nice to meet you". Meeting is an event, so use megismer in the past: Örülök, hogy megismertelek.
8. *Tudok bemenni? for "May I come in?" That asks whether you are physically able. Permission is Bemehetek? (or, from outside, Bejöhetek?).

Where the rule bends

The object test is reliable for people, places and clauses. It gets softer in two spots. First, the colloquial tud + indefinite noun (Tudok egy jó éttermet) overlaps with ismer; either is fine there, but ismer is the non-colloquial choice. Second, texts, songs and lessons can take either verb with a real difference in meaning (can recite vs have come across), so pick by what you mean rather than by the noun. Outside those two, if you catch yourself putting a person after tud or a clause after ismer, switch verbs.

Sources and further reading

• Wiktionary, "tud": the three senses (information, "can" with an infinitive, colloquial acquaintance) and the usage note contrasting ismer and pointing to -hat/-het for permission
• Wiktionary, "ismer": the acquaintance sense, the matching usage note, derived ismerős, ismert and the expressions látásból ismer, hírből ismer
• Wiktionary, "megismer", "felismer" and "ismerős", for the related verbs and the adjective
• Wiktionary, "ért", "képes" and "magyarul", for "understand / be skilled at", "able" and tud magyarul

Frequently asked questions