Questions & Answers about Вчера мы посмотрели первый эпизод нового сериала.
Russian uses two aspects: perfective and imperfective.
- посмотрели is perfective (from посмотреть). It focuses on the completed result: we watched it (and finished it).
- смотрели is imperfective (from смотреть). It focuses on the process or duration: we were watching / we used to watch / we watched (but don’t emphasize finishing).
In this sentence, the idea is that the first episode was watched completely, so perfective посмотрели is natural:
Вчера мы посмотрели первый эпизод… = Yesterday we watched (and finished watching) the first episode…
- Infinitive: посмотреть (perfective).
- Remove the infinitive ending -ть → посмотре-.
- For past tense, you add endings based on gender/number:
- masculine singular: посмотрел
- feminine singular: посмотрела
- neuter singular: посмотрело
- plural (any gender): посмотрели
Since мы (we) is plural, you use посмотрели.