‘-은/ㄴ 지’ is used with a verb, showing a certain period of time has passed after the performance has been done in the first sentence.
● 저는 결혼한 지 10년 됐어요. (I’ve been married for 10 years.)
● 한국에 온 지 8개월 됐어요. (It has been 8 months since I came to Korea.)