Irregular Present: a ști and the 'know' verbs

English has one verb, to know, that does two very different jobs: knowing a fact ("I know that it's raining") and being acquainted with a person or place ("I know Maria," "I know Bucharest"). Romanian, like French and German before it, splits these into two separate verbs — a ști for facts and skills, a cunoaște for acquaintance. Choosing the wrong one is the most common error English speakers make with this pair, because their native language gives them no signal that a choice even exists. This page conjugates both and draws the line between them clearly.

a ști — to know (a fact, a piece of information, how to do something)

A ști is an old, short, irregular verb. Its present is built on a ști- stem, and the only thing to watch is the tu form: it is știi, with a doubled i (the stem's i plus the tu ending -i), pronounced as a slightly lengthened i.

PersonFormMeaning
euștiuI know
tuștiiyou know
el / eaștiehe / she knows
noiștimwe know
voiștițiyou (pl.) know
ei / eleștiuthey know

As with the monosyllabic irregulars, the eu form știu and the ei/ele form știu are identical; the subject or context disambiguates.

Știu unde locuiește, te duc eu acolo.

I know where he lives, I'll take you there.

Tu știi numărul ei de telefon?

Do you know her phone number?

Nu știe nimeni răspunsul.

Nobody knows the answer.

a cunoaște — to know (a person, a place, to be familiar with)

A cunoaște is a Class III (-e) verb with an -sc present (the same -sc / -ști pattern you meet in a crește → cresc, a naște → nasc). Its stem alternates between cunosc- and cunoaște-: the o → oa diphthong appears in the el/ea and noi/voi forms, while cunosc- shows up in eu and ei/ele.

PersonFormMeaning
eucunoscI know / am acquainted with
tucunoștiyou know
el / eacunoaștehe / she knows
noicunoaștemwe know
voicunoaștețiyou (pl.) know
ei / elecunoscthey know

O cunosc pe Maria de când eram copii.

I've known Maria since we were children.

Cunoști un restaurant bun prin zonă?

Do you know a good restaurant around here?

Cunoaște orașul ca-n palmă.

He knows the city like the back of his hand.

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A quick reliability test: if the object is a fact, a clause, or a skill, use a ști. If the object is a person, place, or thing you've become familiar with through experience, use a cunoaște. "I know that..." and "I know how to..." are always a ști; "I know him/her/this city" is almost always a cunoaște.

a ști + să for know-how (skills and ability)

This is where a ști does work English keeps separate as know how to. Romanian uses a ști followed by the conjunctiv with : literally "I know that I (should) swim," meaning "I know how to swim."

Știu să înot, dar nu foarte bine.

I know how to swim, but not very well.

Știi să conduci o mașină cu cutie manuală?

Do you know how to drive a manual car?

Bunica mea știe să facă cele mai bune sarmale.

My grandmother knows how to make the best sarmale.

Note that there is no separate word for "how" here — the -clause alone carries the "how to" meaning. Inserting cum (how) would change the sense: Știu cum să înot leans toward "I know in what manner I should swim," which is unusual and not how you'd express a learned skill.

a ști + că for facts (knowing that something is the case)

For knowing a fact expressed as a full statement, a ști takes (that) plus an ordinary indicative clause — no subjunctive here, because you are reporting something true, not an ability.

Știu că vine mâine, mi-a zis chiar el.

I know that he's coming tomorrow, he told me himself.

Toată lumea știe că prețurile au crescut.

Everyone knows that prices have gone up.

Nu știam că ești și tu invitat.

I didn't know that you were invited too.

The deeper logic: savoir vs connaître, wissen vs kennen

The a ști / a cunoaște split is not a Romanian quirk — it is the same fault line that runs through French (savoir / connaître), German (wissen / kennen), and many other languages. The distinction tracks two kinds of knowing: propositional knowledge (knowing that something is so, or how to do something) versus acquaintance (having met, visited, or experienced someone or something). English used to mark this too — to wit and to ken survive only in fossils like "to wit" and the Scots "do you ken?" — but standard modern English collapsed both into know, which is exactly why English speakers find the split so easy to forget.

Știu povestea, dar nu cunosc autorul.

I know the story, but I don't know (am not acquainted with) the author.

Cunosc Parisul, dar nu știu să vorbesc franceză.

I know Paris (have been there), but I don't know how to speak French.

Common Mistakes

❌ Cunosc că vine mâine.

Incorrect — for a fact-clause with 'că' you need *a ști*, not *a cunoaște*.

✅ Știu că vine mâine.

I know that he's coming tomorrow.

❌ Știu pe Maria de mult timp.

Incorrect — knowing a person is *a cunoaște*, not *a ști*.

✅ O cunosc pe Maria de mult timp.

I've known Maria for a long time.

❌ Tu și românește?

Incorrect — the tu form of *a ști* is 'știi' (doubled i); 'și' means 'and'.

✅ Tu știi românește?

Do you know (how to speak) Romanian?

❌ Știu înot.

Incorrect — know-how needs *a ști* + 'să' + the conjunctiv: 'știu să înot'.

✅ Știu să înot.

I know how to swim.

❌ Noi cunoaștem răspunsul la întrebare.

Misleading — a factual answer is information, so the natural verb is *a ști*: 'știm răspunsul'.

✅ Noi știm răspunsul la întrebare.

We know the answer to the question.

Key Takeaways

  • a ști: știu, știi, știe, știm, știți, știu — for facts (+ ), and skills (+
    • conjunctiv).
  • a cunoaște: cunosc, cunoști, cunoaște, cunoaștem, cunoașteți, cunosc — for people, places, and acquaintance.
  • The split mirrors French savoir/connaître and German wissen/kennen; English merged both into know, so you must consciously choose.
  • "Know that" and "know how to" are always a ști; "know him/her/this place" is a cunoaște.
  • a ști să is the standard way to express a learned ability — no separate word for "how."

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Related Topics

  • The Present Indicative: OverviewA1An introduction to the Romanian present indicative — the workhorse tense that covers both 'I work' and 'I am working' and even the near future.
  • Irregular Present: a da, a sta, a bea, a luaB1How to conjugate four high-frequency monosyllabic irregular verbs — a da, a sta, a bea, and the famously two-stemmed a lua — in the present indicative.
  • Irregular Present Verbs: Consolidated ReferenceB1A one-stop reference gathering the truly irregular present paradigms of Romanian — a fi, a avea, a vrea, a da, a sta, a ști, a lua, a bea — with the high-frequency ones flagged and the patterns that tie them together.
  • Class IV Present: -esc VerbsA2How to conjugate the dominant Class IV subtype that inserts -esc (or back-vowel -ăsc) in the singular and third-person plural — the single most common present-tense pattern in Romanian.
  • The Verb a vrea (to want): PresentA2The present forms of a vrea, its reduced future-auxiliary forms, and why 'want to' becomes a 'să' clause rather than an infinitive in Romanian.