This is the 1657th most frequent Swedish word.
grattis
Congratulations.
Here, 'grattis' is used to express congratulations for the occasion of a birthday.
Grattis på födelsedagen!
Happy birthday!
In this sentence, 'grattis' conveys congratulations related to the achievement of obtaining a new apartment.
Grattis till din nya lägenhet!
Congratulations on your new apartment!
Here, 'grattis' is used to congratulate someone on their academic achievement of graduation.