Сегодня я купил специальный билет на концерт.

I

Breakdown of Сегодня я купил специальный билет на концерт.

• купить: to buy
• на: for
• сегодня: today

Questions & Answers about Сегодня я купил специальный билет на концерт.

Why is купил used here and not покупал?

Russian has two aspects for most verbs: perfective and imperfective.

• купил is past tense, perfective (from купить). It presents the action as a completed, one‑time event: I bought it (the result is done).
• покупал is past tense, imperfective (from покупать). It presents the action as process, repeated, or background: I was buying / I used to buy / I would buy.

In Сегодня я купил специальный билет на концерт, the focus is on the fact of a completed purchase today.
If you said Сегодня я покупал билет на концерт, it could mean something like:

• Today I was in the process of buying a ticket (not necessarily finished), or
• Today I was busy with buying a ticket (focusing on the activity, not the result).

---

Why is it купил and not купила? When do I change the ending?