Breakdown of Я купил клей и цветную бумагу, чтобы приклеить новую обложку к тетради.
я
I
купить
to buy
новый
new
и
and
Questions & Answers about Я купил клей и цветную бумагу, чтобы приклеить новую обложку к тетради.
Why is it купил and not a present-tense form like покупаю?
Купил is the past tense of купить (to buy, perfective).
So Я купил means I bought, not I am buying.
A few useful points:
- купить = perfective, focuses on the completed result
- покупать = imperfective, focuses on the process, repetition, or ongoing action
In this sentence, the speaker is talking about a completed purchase, so купил is the natural choice.
Also, купил tells you the speaker is male.
A female speaker would say Я купила.
Why does бумага become бумагу?
Because бумагу is in the accusative case, since it is a direct object of купил.
The speaker bought what?
- клей
- цветную бумагу
For feminine nouns ending in -а, the accusative singular usually changes:
- бумага → бумагу
- тетрадь would not follow this pattern because it has a different ending
- обложка → обложку
So бумагу is simply the correct direct-object form of бумага.