Hi Sofia,
Thank you for posting! Next time, could you try to put together the sentences in Korean first so that we can help you learn the grammar?
For example, do you need the informal or formal expressions? Is it for work? Or to introduce yourself to a friend? Having said that here is the formal version of your request:
"I work in the Marketing department of a telecom operator" '저는 텔레콤 회사 마케팅부에서 일하고 있습니다'
" I master 4 languages " '저는 4개국어에 능통합니다'
"I have 2 children " '두 자녀를 두고 있습니다'
Best,
Lyn
Team KoreanClass101.com