Present of Být

The present tense of být ("to be") is the highest-priority paradigm in all of Czech. You need it for identity (Jsem student), for existence (Je tu někdo?), and as the helper verb that builds the past tense later on. It is irregular and short, so the whole table can be memorised in an afternoon — but two things about it require real care: the forms are clitics that sit in second position, and the third-person-singular negative is the irregular není.

This page drills the full paradigm and its negatives. For what být does across a sentence — its copula, existential, and auxiliary roles — start with the introduction to být. For every tense and mood gathered together, see the být reference page.

The full present paradigm

Notice how the negatives are perfectly predictable — prefix ne- — except the third singular, where you would expect neje but instead get the fused form není. Burn that exception in now.

Clitics: jsem, jsi, jsme, jste lean on the word before them

Here is the behaviour that separates a learner who knows the table from one who can actually use it. The four forms jsem, jsi, jsme, jste are clitics: unstressed little words that cannot stand alone at the start of a clause. They attach to whatever comes first and slip into the second position.

In English, "I am" is a single stressed unit you can put anywhere. In Czech, the jsem part is a featherweight that has to find a host. So if the sentence opens with an adverb or any other element, jsem does not stay glued to its meaning — it slides to second slot.

You can hear that jsem never carries the stress. The stress lands on unavený or on dnes — never on jsem. That weightlessness is exactly why it can't lead the sentence. (The deeper rules of where clitics line up live on the clitic placement page.)

The third-person forms je and jsou are heavier. They can be stressed, they can open a question, and they behave more like ordinary words — which is one reason they don't share the clitic quirks of jsem and friends.

Být as a copula: identity and description

The most basic use is linking a subject to a noun or adjective — "X is Y." Both affirmative and negative work exactly as the table says.

That last example is worth pausing on. The little word to ("it / that") is extremely common with být when you identify or present something: Je to pravda ("It's true"), Jsou to studenti ("They're students"). Think of to as a neutral pointing word, not as the grammatical subject in the English sense.

Být as an existential verb: "there is / there are"

To say that something exists or is present, use je (singular) or jsou (plural). There is no Czech word corresponding to the English dummy "there."

Word order does the job that English assigns to "there is": the new or existing thing typically follows the verb.

The negative in action — and don't say *neje

The single most common mistake with this paradigm is producing neje for "is not." The correct form is není, full stop. It is one of the first words you will hear in real Czech.

All the other negatives are regular, so once není is automatic, the rest follow the ne- rule without exception.

Common Mistakes

Key Takeaways

• Present of být: jsem, jsi (colloq. seš), je, jsme, jste, jsou.
• Negatives are regular ne- forms — nejsem, nejsi, nejsme, nejste, nejsou — except the irregular 3sg není (never neje).
• Jsem, jsi, jsme, jste are unstressed clitics that must occupy second position (Dnes jsem unavený).
• Je / jsou are heavier and can open clauses and questions.
• Use je / jsou for "there is / there are" — with no word for "there."