The Correlative ten ... který

English builds relative clauses with a single word: "the person who helped me", "the car that I bought". Czech often uses a two-word frame: a demonstrative ten ("the one / that") in the main clause, picked up by a relative pronoun který ("who / which / that") opening the subordinate clause. This is the ten … který correlative, and it is everywhere in spoken and written Czech. The crucial insight — the one that trips up every English speaker — is that ten and který are in different cases, because each belongs to a different clause and answers to a different verb. This page shows you how to keep them apart.

The basic frame

The pattern is: ten stands in the main clause as a pointer, and který opens the relative clause that describes it.

Notice the comma before který. Czech always puts a comma in front of a relative clause — it is not optional the way English commas often are. The relative pronoun který agrees in gender and number with its antecedent (the thing it refers back to), but takes its case from its job inside the relative clause.

The two pronouns carry independent cases

This is the heart of the matter. Look at this sentence:

• toho is accusative — it is the direct object of znám ("I know"). Znát governs the accusative, so the demonstrative is toho (masculine animate accusative), not ten.
• který is nominative — it is the subject of udělal ("did") inside the relative clause. Whoever did it is the doer, hence the nominative.

Same sentence, two different cases on the two pronouns, decided entirely by their own clauses. Now flip the roles:

• Ten is nominative — it is the subject of je ("is") in the main clause.
• koho is accusative — it is the object of viděl ("saw") in the relative clause. (Here the relative pronoun for a person is kdo → koho; see below.)

The cases have swapped compared with the previous example, and that is exactly the point: they move independently.

Here tomu is dative (the recipient of dej, "give"), while kdo is nominative (the subject of přijde, "comes"). Three different cases would be no surprise in a longer sentence.

Dropping ten when there's a noun

When the antecedent is a spelled-out noun, you usually don't need a separate ten — the noun itself is the antecedent and který attaches straight to it.

You can add ten for emphasis or to disambiguate — ta žena, která… ("that woman, the one who…") — but it isn't required. Czech does this far less reflexively than the bare correlative below.

ten standing alone: "the one who", "he who"

When there is no noun and you mean "the one who", "the person that", or the generic "whoever", the demonstrative has to be present — it is now the only thing the relative clause can hang on.

Two relative pronouns share this job:

• kdo ("who") for people, when the reference is generic: ten, kdo… ("the one who…", "whoever").
• co ("what") for things and abstractions: to, co… ("the thing that…", "what…").

Note the demonstrative gender: a generic person takes masculine ten, while a thing or whole idea takes neuter to. To, co is the standard way to render English "what" in the sense of "the thing which".

In the first of those, ty is masculine animate accusative plural (object of nesnáším) and kteří is masculine animate nominative plural (subject of lžou) — independent cases again, and independent number agreement working correctly because the antecedent is plural.

který agrees in gender and number, not case

To pick the right form of který, do two things in order:

1. Find the antecedent and copy its gender and number onto který: muž → který, žena → která, auto → které, lidé → kteří.
2. Find the verb or preposition inside the relative clause and take the case it demands.

Here která is feminine (from kavárna) but stands in the locative které because of the preposition v inside the relative clause. The full declension of který is laid out on the který declension page.

kterému is masculine animate (from člověka) and dative, because věřit ("trust") governs the dative.

Common mistakes

The signature English-speaker error is forcing ten and který into the same case because, in English, "the one who" feels like a single unit.

The reverse error — copying the main-clause case onto the relative pronoun:

Using který where a bare generic needs kdo:

Dropping the comma before the relative clause:

Making který agree in case with its antecedent instead of with its own clause:

Key takeaways

• ten … který links a main-clause pointer to a relative clause; the comma before který is obligatory.
• ten takes its case from the main clause; který takes its case from the relative clause. They are independent.
• který copies its antecedent's gender and number, but never its case.
• For a standalone generic, use kdo (people) or co (things): ten, kdo…, to, co….

To drill the difference between ten and který themselves, see ten vs který; for the generic relatives in depth, see kdo and co.