-ávat / -ívat

1. Formation and Morphology
Iteratives are formed from imperfective verbs. The suffix -vat is added to the imperfective stem, which lengthens or changes the preceding theme vowel (a → á, i → í, e or ě → í or á). For example: dělat → dělávat, chodit → chodívat, bydlet → bydlívat, sedět → sedávat. For short or monosyllabic verbs lacking a standard theme vowel, the suffix -vat is simply added to the existing stem (e.g., být → bývat, pít → pívat); note that their root vowels are long compared to their short past tense forms (e.g., byl → býval, pil → píval). Note that some high-frequency verbs reveal their underlying root consonant in the first-level iterative form, which is also visible in other forms like the past or present tense (e.g., jíst → jídat / jedl, číst → čítat / čtu). Furthermore, some verbs form double iteratives by stacking suffixes, passing through an intermediate frequentative form (e.g., vidět → vídat → vídávat, slyšet → slýchat → slýchávat, jíst → jídat → jídávat, or číst → čítat → čítávat). Czech even allows stacking these suffixes for extreme temporal distance (e.g., the past tense form chodívával from the double-iterative infinitive chodívávat, not to be confused with the standard iterative past chodíval), though this is rare and sounds archaic or folksy. When dealing with indeterminate verbs of motion (which already express habitual movement, like chodit - to go regularly), the iterative form (chodívat) emphasizes occasional repetition or a habit that used to happen. All iteratives ending in -ávat and -ívat fall into the 5th verb class and conjugate entirely regularly with -ám, -áš, -á, -áme, -áte, -ají (e.g., chodívám, chodíváš...).

2. Tense Usage

• Present Tense: They mean "usually do" or "tend to". High-frequency iteratives like bývat (to tend to be) and mívat (to usually have) are ubiquitous in daily speech. While learners will encounter iteratives overwhelmingly in the past tense, present tense forms are also reasonably common for verbs of perception and frequent activities (e.g., the double iteratives vídávat, slýchávat, or standard iteratives like hrávat). Important: A present tense iterative can never be used for an action happening right now at the moment of speech. For example, Nosívám tašku means "I usually carry a bag," but it can never mean "I am carrying a bag right now."
• Past Tense: They mean "used to" or habitual "would". They emphasize that the habit belonged to a specific, now-closed period in the past.
• Future Tense: Iteratives can be used in the future tense (e.g., budu dělávat) by native speakers to emphasize mundane, everyday future repetitions, though learners can generally revert to the plain imperfective (e.g., budu chodit) to express a repeated action in the future. Note: While you might hear forms like budu dělávat in real life, traditional textbooks and exams often consider future iteratives incorrect, so it is safer to stick to plain imperfectives for future habits.

3. The "Habitual Would" Trap
English speakers often use "would" for past habits (e.g., "Every summer we would go to the lake"). Never translate this with the present conditional (bych). You must use the iterative or plain imperfective past.

4. Aspectual Nature
Iteratives are strictly imperfective. They are inherently unbounded and emphasize the regularity of an action over time. You cannot use them for a single bounded event.

5. The Secondary Imperfective Trap
Do not confuse true iteratives with secondary imperfectives. The exact same suffixes (-ávat, -ívat, -vat) are used to create secondary imperfectives from prefixed perfective verbs (e.g., vydělat → vydělávat). These prefixed forms carry a standard imperfective meaning, not an iterative "used to" meaning. While a prefixed verb ending in -ávat or -ívat is often a secondary imperfective, true iteratives can also have prefixes when derived from prefixed imperfectiva tantum (e.g., vyprávět → vyprávívat, závidět → závidívat) or when built on top of secondary imperfectives (e.g., přicházet → přicházívat).