martwić się o coś in English:

1. worry about something

English word "martwić się o coś"(worry about something) occurs in sets:

Unit 3 - Art all around us.
22. Feelings and emotions
Beyond Prepositions 14
ZWROTY STANAG 2
rules and regulations

2. be worried about something

English word "martwić się o coś"(be worried about something) occurs in sets:

Adjectives plus prepositions
Angielski słówka dział 7
lista słowek 3

3. fret about something