bym / byś / byśmy / byście

The conditional mood (tryb przypuszczający) is essential for navigating social situations and hypothetical scenarios in Polish.

1. Formation
To form the conditional, you start with the 3rd person past tense form (the l-participle) and add the following particles:

• -bym: 1st person singular (I would)
• -byś: 2nd person singular (You would)
• -by: 3rd person singular/plural (He/She/It/They would)
• -byśmy: 1st person plural (We would)
• -byście: 2nd person plural (You all would)

2. Gender and Number Agreement
Because these particles attach to the past tense, the verb itself must reflect the gender and number of the subject. For example, a man says zrobiłbym, while a woman says zrobiłabym. For the 3rd person plural, while the particle -by remains the same, the verb stem must change to reflect the virile or non-virile subject (e.g., zrobiliby vs. zrobiłyby).

3. Orthography (Writing Rules)
The spelling of these particles depends on the grammatical form they follow:

• Joined: They are written as one word when attached to personal verb forms (e.g., chciałbym, poszlibyście) and lexicalized conjunctions like gdyby, żeby, or iżby.
• Separate: They are written as separate words when they follow impersonal forms ending in -no/-to (e.g., zrobiono by, podano by), infinitives (e.g., zrobić by), or other parts of speech like pronouns, nouns, and adverbs (e.g., Ja bym to zrobił, Chętnie bym poszedł). Additionally, following the January 1, 2026 spelling reform by the Polish Language Council, conditional particles must be written separately from other conjunctions and particles (e.g., czy by, bo by, to by).

4. Placement and Mobility
While usually attached to the verb, these are mobile clitics. They can move to the second position in a sentence or occur in established conjunctions such as gdyby and żeby. Follow the spelling distinctions above rather than freely joining by to every conjunction.

5. Stress (Pronunciation)
In formal Polish, adding these particles does not shift the stress to the penultimate syllable. The stress remains on the same syllable as the original 3rd person past tense form. For example: ku-PI-ła-bym (not kupi-ŁA-bym). In the 1st and 2nd person plural forms (e.g., zrobilibyśmy, kupilibyście), the stress falls on the fourth syllable from the end in prescriptive Polish. However, in everyday spoken Polish, you will constantly hear the stress shifted to the penultimate syllable (e.g., kupi-ŁA-bym, zrobili-BY-śmy), which is extremely common and widely accepted in informal speech.

Three Practical Uses: A hypothesis imagines a condition: Gdybym miał czas, pojechałbym (If I had time, I would go). A polite request softens a demand: Czy mógłbyś otworzyć okno? (Could you open the window?). A wish or preference says what someone would like: Chętnie odpoczęłabym w domu (I would gladly rest at home). Choose the person particle and the gender/number form independently in each sentence.