Aspect   •   Conjugation (Infinitive stems and present tense stem   •   Present   •   Past   •   Future   •   Conditional   •   Imperative   •   Participles, gerund   •   Passive voice)   •   Irregular verbs


One of the greatest nightmares of people learning a Slavic languages are verbs, which are characterized by many different conjugations, exceptions and exceptions on exceptions. Perhaps the hardest thing for non-Slavs to get used to is lexical aspect: most verbs exist in two different forms („aspects”), perfective and imperfective. Most perfective verbs have an imperfective counterpart and vice versa. Usually, they need to be learned separately. Complicated as this may be for foreigners, it is a very characterstic feature of Slavic, omnipresent in all Slavic languages, and therefore cannot be avoided. All we can do is make the system as transparent and regular as possible. Still, both forms, perfective and imperfective, are listed separetely in the dictionary.

In short, perfective aspect focuses on the result of an action and not on the action itself. Depending on tense, it means that the action has been completed already or will be completed at some point. Imperfective aspected, on the other hand, focuses on action itself; it indicates that on the point of reference the action is or was going on. It can also express a an ongoing process, a habit or a repeated action: ja čital jesm knigų (imperfective) means „I was reading a book” or „I have been reading a book”, ja pročital jesm knigų (perfective) means „I have read a book (and finished it)”.

Verbs without a prefix are imperfective almost by definition. Most imperfective verbs have a perfective equivalent that means exactly the same thing, except that it focuses on the result of the action. In general, this perfective version is formed by adding a prefix:
dělati (impf.) > sdělati (pf.) „to do”
čistiti (impf.) > počistiti (pf.) „to clean”
pisati (impf.) > napisati (pf.) „to write”

However, the general purpose of placing a prefix in front of a verb is modifying its meaning. Whereas in the case of pisati the prefix na- simply turns it into a perfective verb, other prefixes can be used as well, for example za- in zapisati „to record, to register”. Because this is a perfective verb, a „secondary” imperfective verb is needed that is based on its perfective equivalent. These imperfective verbs are formed as follows:

Sometimes aspect pairs are irregular, for example nazyvati (impf.)/nazvati (pf.) „to call, to name”, prihoditi (impf.)/prijdti (pf.) „to come”, podimati (impf.)/podjęti (pf.) „to take up, to undertake”.

A special category of verbs in terms of aspects are verbs of motion. Unlike other verbs, they usually make a three-way distinction: non-directional imperfective, directional imperfective, perfective. The first of these expresses movement without any particular direction, and therefore has no perfective equivalent of its own. For example:

non-directional directional impf. perfective
to go (by foot) hoditi idti pojdti
to by (by transport) jězditi jěhati pojěhati
to fly lětati letiti poletiti
to run běgati běgti poběgti
to climb laziti lězti polězti
to crawl pòlzati pòlzti popòlzti
to fall padati pasti upasti
to carry nositi nesti ponesti
to transport voziti vezti povezti
to lead voditi vesti povesti

For example: Igor jězdil po Moskvě „Igor was driving around in Moscow”. Igor jěhal do Moskvy „Igor was driving do Moscow”. Igor pojěhal do Moskvy „Igor has gone to Moscow”.

When a non-directional verb of motion has a direction anyway, this expresses a habit: Igor jězdil do Moskvě „Igor [always|often] went to Moskow”.

Except for hoditi, idti and pojdti, there is also the word pohoditi, which can express „to walk a bit”, but also „to walk in multiple directions”.

In compounds with a prefix, the non-directional form is used for the imperfective verb, the directional form for thee perfective verb:
odhoditi (impf.)/odidti (pf.) „to go away”
dolětati (impf.)/doletiti (pf.) „to arrive (by flight)”
prinositi (impf.)/prinesti (pf.) „to bring”


Aspect is one thing that might take a while getting used to, conjugation is another. The Slavic languages are characterised by a large number of different conjugations, combinations of conjugations („classes”), exceptions and irregular verbs. In addition to this, the Slavic languages have a varying number of moods and tenses, and three languages (Slovene, Upper and Lower Sorbian) have separate forms for the dual. Verbal conjugation in Interslavic is simplified to the highest possible extent, while still preserving naturalism and without resorting to artificial solutions. As a result:

Infinitive stem and present tense stem

In the dictionary, verbs are always given in the infinitive. All infinitives have the ending -ti: dělati „do, make”, uměti „can, to be able”, prositi „to ask”, nesti „to carry”, pisati „to write”, čuti „to feel”, dękovati „to thank”, tęgnųti „to pull”. Usually, knowing the infinitive is enough for knowing the entire conjugation of a verb.

The infinitive stem is created by simply removing the ending -ti, and serves as a starting point for the past tenses, the conditional, the past participles and the verbal noun.

Infinitives are almost always regular, so that the ending -ti does not alter the infinitive stem. This is also the case in verbs like mogti „can”, pekti „to bake”, běgti „to run” etc. (instead of the expected but less transparant moći, peći and běći). The only exceptions are verbs on -sti: in most cases, their infinitive stems end in d, sometimes also t or s. For example klasti „to lay, to put”, pasti „to fall” and gnesti „to crush” have the stems klad-, pad- and gnet-. To distinguish these cases from nesti (stem: nes-) and the like, they are represented in the dictionary as follows: klasti (klad-e), gnesti (gnet-e).

Usually, the present tense stem (used for the present tense, the imperative and the present participles) can be derived regularly from the infinitive stem. There is a difference between the first and the second conjugation:

A number of verbs use a separate root in the present tense. In most cases, these are verbs of the mixed a/j, a/i and ě/i classes in Slavic. An active user of Slovianski will have to learn both forms. He will notice, however, that in most cases the formation of this second root happens in a predictable way. Whenever the present-tense stem cannot be derived from the infinitive by applying the rules above, it will be given in the dictionary. A few examples: pisati (piš-e) „to write”, htěti (hoć-e) „to want”, spati (sp-i) „to sleep”, zvati (zov-e) „to call”, brati (ber-e) „to take (impf.)”, vzęti (vòzm-e) „to take (pf.)”.

Present tense

In the present tense, the endings for the two conjugations are the following:

The West and South Slavic languages also have a third conjugation, based on contraction of -aje- sequences. In this case, the present tense stem is truncated:


First conjugation Second conjugation
infinitive dělati nesti hvaliti
present-tense stem dělaj- / děl- nes- hval-i-
ja dělajų / dělam nesų hvaljų
ty dělaješ / dělaš neseš hvališ
on/ona/ono dělaje / děla nese hvali
my dělajemo / dělamo nesemo hvalimo
vy dělajete / dělate nesete hvalite
oni dělajųt nesųt hvalęt


Past tense

Basically, there are two different methods for dealing with the past tense. The simplest solution is provided by the „Russian approach”, in which only the so-called L-participle is used. It is formed by adding the ending -l (masculine singular), -la (feminine singular), -lo (neuter singular), -li (plural) to the infinitive stem. In Interslavic, it is best (though not obligatory) to add a form of byti in the 1st and 2nd person. Examples:

infinitive dělati nesti hvaliti
infinitive stem děla- nes- hvali-
ja (jesm) dělal(a) (jesm) nesl(a) (jesm) hvalil(a)
ty (jesi) dělal(a) (jesi) nesl(a) (jesi) hvalil(a)
my (jesmo) dělali (jesmo) nesli (jesmo) hvalili
vy (jeste) dělali (jeste) nesli (jeste) hvalili
oni dělali nesli hvalili

One verb has an irregular past tense: the verb idti „to go” has šel, šla, šlo, šli „went” (sometimes written was išel etc.). This goes for its compounds as well.

Thus, an imperfect tense is created by applying this system to imperfective verbs, a perfective tense by applying it to perfective verbs: ja jesm dělal „I did”, „I was doing”; ja jesm sdělal „I have done”.

Additional past tenses

Old Church Slavonic, as well as most South Slavic languages, use a more complex solution, distinguishing between the imperfect, perfect and pluperfect tenses, as well as the aorist. Interslavic projects in the 19th century tend to follow this model. Novosloviensky adopts it as well, but simplifies it somewhat by merging the imperfect tense with the aorist. This solution (having the imperfect tense but not the aorist) is mostly justified by their similarity in endings, but does not exist anywhere in Slavic.

The primary purpose of distinguishing between various past tenses is allowing the writer some stylistic variation. It should be understood, however, that for a vast majority of Slavs, the endings are not understandable at all. In communication with Poles, Russians etc. it is wiser to avoid them. Besides, it is better not to use them if you don't know precisely how to use them, even in communication with South Slavs.

Imperfect tense

The imperfect tense denotes an action that was taking place somewhere in the past. It is formed by adding the following endings to the infinitive stem:


infinitive dělati nesti hvaliti
infinitive stem děla- nes- hvali-
ja dělah neseh hvalih
ty dělaše neseše hvališe
on/ona/ono dělaše neseše hvališe
my dělahmo nesehmo hvalihmo
vy dělaste neseste hvaliste
oni dělahų nesehų hvalihų


Perfect tense

Like the normal past tense in Interslavic, the perfect tense combines the aforementioned L-participle with the present tense of the verb byti „to be”. Only its meaning is narrowed down to an action performed in the past as reflected in the present: ja jesm dělal „I have been doing”, ja jesm sdělal „I have done”.

Pluperfect tense

At last, the pluperfect tense is formed by combining the L-participle with the imperfect of byti. Unlike in the case of the perfect tense, the moment of reflection is in the past and refers to an action performed before that: Ja běh dělal „I had done”.

Future tense

The future tense is formed by combining the future tense of the verb byti „to be” with the infinitive. The forms are the same as if a verb with the stem bųd- were conjugated in the present tense. Examples:

infinitive dělati
ja bųdų dělati
ty bųdeš dělati
on/ona/ono bųde dělati
my bųdemo dělati
vy bųdete dělati
oni bųdųt dělati



The conditional can be formed in two ways:

Short form Long form
infinitive stem
ja by dělal(a) byh dělal(a)
ty by dělal(a) bys dělal(a)
by dělal
by dělala
by dělalo
by dělal
by dělala
by dělalo
my by dělali byhmo dělali
vy by dělali byste dělali
oni by dělali byhų dělali

If really needed, a past conditional can be formed by inserting the paste tense of the verb „to be” into the normal conditional form:


The imperative has forms for the 2nd person singular, the 1st person plural and the 2nd person plural: dělaj „do!” (to one person), dělajmo „let's do!”, dělajte „do!” (to more persons). It is formed by adding -i to the present tense stem (-j after a vowel, after j). Examples:

First conjugation Second conjugation
infinitive dělati nesti hvaliti
present-tense stem dělaj- / děla- nes- hval-i-
2sg. dělaj nesi hvali
1pl. dělajmo nesimo hvalimo
2pl. dělajte nesite hvalite


Participles and gerund

Except for the aforementioned L-participle, there are four participles in Interslavic: present active, present passive, past active, past passive.

The present active participle is derived from the present tense stem of an imperfective verb, adding -ųći in the first conjugation and -ęći in the second. In other words, it is built by replacing the ending -t of the 3rd person plural by -ći. For example: dělati > dělajųći „doing”, hvaliti > hvalęći „praising”. It is inflected like an adjective of the soft type: běgajųći mųž „the running man”, ljubęća mati „a loving mother”.
The adverbial present active participle (also known as „transgressive”) has the same ending, but is not inflected for gender: Idųći do råboty, ona vsěgda dymi cigaretojų „While going to her work, she always smokes a cigarette”.

The past active participle is based on the infinitive stem of a perfective verb, followed by -vši if it ends in a vowel or -ši if it ends in a consonant. For example: sdělati > sdělavši „having done”, ukrasti (< ukrad-ti) > ukradši „having stolen”. Like the present active participle, it can both be adjectival and adverbial, but its usage as an adjective is very rare. Note that the past active particple is a very bookish form that exists in most Slavic languages, but is hardly ever used in spoken Slavic. Using it is therefore not recommended.

The present passive participle is derived from the present tense stem as well, adding -omy (-emy after a soft consonant) in the first conjugation and -imy in the second: dělajemy „being done”. It should be understood that this participle is not used at all in several Slavic languages, and that remnants of it can have slightly different meanings, for example vidimy means „visible” rather than „being seen”.

The past passive participle is formed by adding -ny to the infinitive stem when the latter ends in a vowel, and -eny when it ends in a consonant: dělany „done”, neseny „carried”. However:

A verb can very simply be converted into a noun (gerund, verbal noun) by substituting the ending -ny of the perfect past participle by -nje (or -ty by tje). Examples: dělanje „(the act of) doing”, pitje „drinking”. Instead of -je, equally correct are -’je or the somewhat archaic ending -ije: dělańje/dělanije, piťje, pitije.


First conjugation Second conjugation
infinitive dělati nesti hvaliti
infinitive stem děla- nes- hvali-
present-tense stem dělaj- / děla- nes- hval-i-
present active part. dělajųći nesųći hvalęći
present passive part. dělajemy / dělamy nesomy hvalimy
past active part. dělavši nesši hvalivši
past passive part. dělany neseny hvaljeny
gerund dělanje nesenje hvaljenje

The passive voice

The passive voice is created by combining a form of the verb byti „to be” with a passive participle. In the present tense, this participle can be the past passive participle or the present passive participle of an imperfective verb:

Irregular verbs


The only truly irregular verb is byti „to be”. It is conjugated as follows:

present imperfect past future conditional imperative
1sg jesm běh byl, byla, bylo bųdų byh
2sg jesi běše bųdeš bys bųď
3sg jest (je) běše bųde by
1pl jesmo běhmo byli bųdemo byhmo bųďmo
2pl jeste běste bųdete byste bųďte
3pl sųt (jesųt) běhų bųdųt byhų (by)
present active part. sųći
infinitive byti past active part. byvši
gerund bytje future active part. bųdųći

Dati, jesti, věděti

The verbs dati „to give”, jěsti „to eat” and věděti „to know” have an irregular present tense. Like byti, they belong to the so-called athematic conjugation, meaning that they have their root ending in a vowel. In the present tense, they are inflected as follows:

infinitive dati jěsti věděti
present-tense stem da- jě- vě-
ja dam jěm věm
ty daš jěš věš
on/ona/ono da
my damo jěmo věmo
vy date jěste věte
oni dadųt jědųt vědųt

Other forms of these three verbs are formed regularly.


The verb idti „to go” is conjugated regularly, except for the L-participle šel (f. šla, n. šlo) and the (related) past active participle šedši. Sometimes these forms are preceded by i-: išel, išla etc.

The infinitive idti is sometimes written iti.