Past Tense

To form the past tense, you generally drop the -ć from the infinitive and add a past tense suffix (-ł- or -l-), followed by a personal ending. Verbs ending in -c, -ść, or -źć do not follow this rule and have irregular past stems. A foundational example is the verb być (to be): byłem/byłam (I was), byłeś/byłaś (you were), był/była/było (he/she/it was), byliśmy/byłyśmy (we were), byliście/byłyście (you were), byli/były (they were).

Singular Endings:

• Masculine: -łem, -łeś, -ł (e.g., czytałem - I read)
• Feminine: -łam, -łaś, -ła (e.g., czytałam - I read)
• Neuter: -ło (e.g., czytało - it read)

Plural Endings:

• Masculine-Personal Plural (Virile): -liśmy, -liście, -li. Used with masculine-personal nouns and pronouns, including a mixed group of people referred to as my or oni. Noun class still matters: dzieci czytały even when the children include boys.
• Non-Masculine-Personal Plural (Non-virile): -łyśmy, -łyście, -ły. Used for groups of women, children, animals, and objects.

Note on Stress: In Polish, word stress usually falls on the second-to-last (penultimate) syllable. Prescriptively, the 1st and 2nd person plural past tense endings (-śmy and -ście) do not shift the stress, meaning it falls on the third-to-last (antepenultimate) syllable (e.g., czy-TA-li-śmy). However, in colloquial Polish, native speakers frequently regularize this to penultimate stress (e.g., czy-ta-LI-śmy).

Mobile Endings: The personal endings (-m, -ś, -śmy, -ście) can detach from the verb and attach to selected earlier words in the clause, especially question words, conjunctions, particles, and pronouns such as myśmy (e.g., Gdzie byłeś? can become Gdzieś był?). When attaching to a word ending in a consonant, both singular and plural endings take a linking -e-, becoming -em, -eś, -eśmy, and -eście (e.g., jak + śmy = jakeśmy).

Important Vowel Shifts:
Some verbs change their stem vowels in the past tense. Many verbs ending in -eć (like mieć - to have) change e to a before the hard consonant ł, but keep the e before the soft consonant l. Practically, this means a appears in all singular forms and the non-virile plural (e.g., miałem, miała, miały), while e is preserved only in the virile plural (e.g., mieliśmy, mieli). Similarly, verbs ending in -eść or -eźć (like nieść - to carry) shift e to o or ó before hard consonants (e.g., niósł, niosła), but keep e before the soft l in the virile plural (e.g., nieśli). Additionally, verbs retaining a nasal past stem from -ąć (like zacząć - to start) change the nasal vowel ą to ę in all forms except the masculine singular (e.g., zacząłem vs. zaczęłam). Finally, many irregular verbs experience an o to ó vowel shift specifically in the masculine singular past tense, reverting to o for all other genders and plurals (e.g., móc becomes mógł, but mogła, mogli).

Irregular Verbs:
Some common verbs are highly irregular in the past tense. For example, iść (to go) becomes szedł, szła, szli, and móc (to be able to) becomes mógł, mogła, mogli.

Remember: English speakers often look for a "past continuous" tense (I was reading). In Polish, you simply use the imperfective/perfective aspect of the verb in this single past tense structure. Imperfective verbs are used for ongoing or repeated actions (like "was reading" or "used to read"), while perfective verbs are used for single, completed actions (like "read" or "has read").

Keep the ending on the verb as the neutral learning model. Detached endings vary by expression and style: myśmy czytali is established usage, whereas attachment to an ordinary noun, as in książkęś czytał, is markedly literary, regional or old-fashioned. Not every first word is an equally natural host.