Present conditional

The present conditional is an essential feature of everyday Czech, used for hypotheticals, wishes, and crucially, for politeness.

1. Formation
It combines the conditional auxiliary with the past participle (l-participle). The participle must agree with the subject in gender and number.

• Já: bych dělal/a
• Ty: bys dělal/a
• On/ona/ono: by dělal/a/o
• My: bychom dělali/y
• Vy: byste dělali/y
• Oni/ony/ona: by dělali/y/a

2. Word Order
The auxiliary is a strict second-position clitic. It must immediately follow the first stressed word or phrase. Note that coordinating conjunctions like a (and), ale (but), and nebo (or) do not count as the first position, meaning the auxiliary must come after the next word (e.g., Ale já bych..., never Ale bych já...). While the standalone auxiliary cannot start a clause, the fused conjunctions discussed below (like kdybych or abys) can and frequently do. When multiple clitics are present, they follow a strict internal order: Auxiliary (bych) → Reflexive (se/si) → Dative (mi/ti/mu) → Accusative (ho/to/je). For example: Koupil bych si to. (I would buy it for myself).

3. Fusions and Conjunctions
The auxiliary fuses with certain words to create the conjunctions kdyby (if) and aby (so that). The conjugated forms look like kdybych, abys, kdybychom. Because these conjunctions already contain the conditional auxiliary, the verb that follows them must be a bare l-participle (e.g., kdybych dělal). Crucially, aby is not only used for purpose clauses, but is also the mandatory way to express wanting someone else to do something. You cannot use an infinitive for this in Czech; instead, you must use a clause with aby (e.g., Chci, abys to udělal - I want you to do it). In the 2nd-person singular, the -s from bys fuses with reflexive pronouns to form by ses and by sis (never bys se). This mandatory fusion also applies to conjunctions, so you must write kdyby ses and aby sis (never kdybys se or abys si).

4. Negation
To form the negative conditional, the negative prefix ne- attaches to the l-participle (e.g., nedělal bych), and never to the conditional auxiliary.

5. Real vs. Unreal Conditions
It is crucial to distinguish between hypothetical and real conditions. The conjunction kdyby is only used for unreal or hypothetical conditions. For real possibilities, use jestli or pokud with the indicative mood (e.g., jestli bude pršet).

6. Register and Spelling Rules
There is a major difference in the 1st-person plural ('we would'):

• bychom: The standard, formal form required in writing.
• bysme: The colloquial form used naturally in everyday spoken Czech.

Note: You may see native speakers write by jsme or by jste online, as well as singular errors like by jsem, bysem, or by jsi. These are widespread spelling errors. The correct forms are always bychom, byste, bych, and bys.

7. Pragmatic Politeness
The conditional is the standard way to soften requests and offers. A blunt Chci kávu (I want coffee) becomes a polite Chtěl bych kávu (I would like coffee).