rozchmurz się in English:

I brought in some flowers to cheer up the room.

Last year in London, twenty tons of presents were donated, wrapped, and delivered to a local hospital to cheer up sick children who couldn't go home for Christmas.

„Hey Pam, cheer up! You shouldn’t worry about this stupid thing!”

Come on, cheer up! It’s not the end of the world!

cheer up I am sure things will get better tomorrow

to cheer up our mood