This is the 406th most frequent Swedish word.
köpa
"To buy."
The verb 'köpa' is used in its infinitive form, indicating the action of buying.
Jag tänker köpa en ny bok.
I am planning to buy a new book.
The verb 'köpte' is in the past tense, indicating the action of buying that has already occurred.
Maria köpte ett par skor igår.
Maria bought a pair of shoes yesterday.
The verb 'köpa' is used in the infinitive form within a question, indicating a request for the action of buying.