The past tense: one form for every person
The Russian past is -л / -ла / -ло / -ли. It marks gender and number, never person, and needs no auxiliary verb whatsoever.
Build the past by taking the infinitive, dropping -ть and adding -л for masculine, -ла for feminine, -ло for neuter and -ли for plural: чита́ть → чита́л, чита́ла, чита́ло, чита́ли. If the stem already ends in a vowel you simply add the endings to it, so знать → знал, чита́ть → чита́л, се́ять → се́ял. There is no person marking at all: я чита́л and он чита́л contain the identical verb form. Compare Italian, where a past tense needs an auxiliary, a participle and agreement; Russian needs four endings and nothing else.
Agreement is with the subject, in gender and number: Ма́ма рабо́тала, Па́па рабо́тал, О́кно бы́ло закры́то, Де́ти игра́ли. Because the verb itself carries the gender, the pronoun is often unnecessary — Рабо́тал can mean 'he worked' or 'I worked', and the context resolves it. This is why Russian can sound so economical.
A small group of verbs is irregular, and the pattern is worth learning as a pattern rather than as a list: the masculine is shorter than the other three forms. Идти́ → шёл, шла́, шло, шли (the л vanishes). Мочь → мог, могла́, могло́, могли́. Не́сти → нёс, несла́. Вести́ → вёл, вела́. Цвети́ → цвёл, цвела́. Быть → был, была́, бы́ло, бы́ли. Ждать → ждал, ждала́, жда́ло, жда́ли, with the stress wandering. There are no others you need at this level.
Finally, the past is where aspect first becomes audible. The past of an imperfective verb describes a process, a habit or a bare fact; the past of a perfective verb describes a completed action with a result in hand. Я чита́л кни́гу means 'I was reading the book', or simply 'I read it at some point' — it says nothing about whether you finished. Я прочита́л кни́гу means 'I read the book and got to the end'. Same tense, different verb. The full treatment is under aspect.
Examples
- Вчера́ я чита́л. Yesterday I was reading. Listen in Russian: Slow in Russian: Вчера́ я чита́л.
- Она́ рабо́тала до́ма. She worked at home. Listen in Russian: Slow in Russian: Она́ рабо́тала до́ма.
- Де́ти игра́ли в па́рке. The children were playing in the park. Listen in Russian: Slow in Russian: Де́ти игра́ли в па́рке.
- Он шёл домо́й. He was walking home. — the irregular past of идти́ Listen in Russian: Slow in Russian: Он шёл домо́й.
- Мы бы́ли в Ита́лии. We were in Italy. Listen in Russian: Slow in Russian: Мы бы́ли в Ита́лии.
- Я прочита́л э́ту кни́гу. I read this book and finished it. — perfective past Listen in Russian: Slow in Russian: Я прочита́л э́ту кни́гу.