The imperfect tense

Open a book of Serbian folk tales, or a novel written a hundred years ago, and you will meet past-tense verbs you have never been taught: Bijaše jednom jedan car…, Starac gledaše u vatru, Reka tecijaše kroz dolinu. These are forms of the imperfekat (the imperfect) — the last of the Serbian past tenses. You will almost never need to make one yourself; where a book says gledaše, you would say je gledao. But you need to recognise it, because it is everywhere in older and literary prose.

What it means

The imperfect describes a past action in progress — something that was going on, lasting, or happening again and again — the background of a story. English usually renders it with was …-ing or used to. It is built almost only from imperfective verbs, which already tells you its job: it paints the scene, it does not move the story on.

The one imperfect still alive: biti

Only biti keeps its imperfect in everyday speech. The 3rd person singular beše turns up in conversation in a fixed use: when you are trying to recall something you once knew — Kako se beše zove? "What was his name again?", Ko beše to? "Who was that again?". In storytelling the longer bijaše is the classic fairy-tale opening: Bijaše jednom jedan car "Once upon a time there was a tsar".

In practice you will meet two forms far more than all the rest: beše (he/she/it was) and behu (they were). Behu to teška vremena — "Those were hard times".

How to recognise any other verb in the imperfect

Every imperfect has a vowel -a- (or -ija-) followed by one of six endings. Learn the endings and you can spot the tense anywhere. Notice that ti and on/ona share the same form, so only the context tells you who.

• a-verbs (present -am: gledam, čekam, pevam) — the endings go straight onto the infinitive stem: gledaše, čekaše, pevaše, pričaše, imaše, padaše. These are the easiest to recognise: they look like the infinitive with -še or -hu in place of -ti.
• i-verbs (present -im: nosim, vodim, mislim, živim) — the last consonant of the stem softens before -a-, exactly as in the passive participle you already know (jotation): nositi → nošaše, voditi → vođaše, misliti → mišljaše, živeti → življaše. After r nothing softens: govoriti → govoraše.
• e-verbs (present -em: pišem, plačem, idem, tečem) — if the infinitive ends in -ati, the imperfect is built from that infinitive: pisati → pisaše, plakati → plakaše, zvati → zvaše. The other e-verbs build it on the present stem, often with -ija-: teći → tecijaše, ići → iđaše, moći → mogaše, piti → pijaše.

Imperfect or aorist?

You already know the aorist (reče, ode, uđe, ugleda). Both are one-word literary past tenses, and both have a 3rd singular that can look similar, so they are worth telling apart. The aorist reports a single completed event that moves the story forward, and is made from perfective verbs. The imperfect describes what was going on around that event, and is made from imperfective verbs. A typical literary sentence uses both: the imperfect sets the scene, the aorist breaks into it.

The trap: an aorist 3rd PLURAL can end in -še too (ugledaše = they caught sight of). Do not stop at the ending — ask whether the verb is perfective. ugledati is perfective, so ugledaše is an aorist. The imperfect 3rd plural always ends in -hu, never -še.

Kraljević ugleda devojku koja pevaše kraj reke. — The prince caught sight of (aorist: one moment) a girl who was singing (imperfect: going on all along) by the river.