Question

이것은 내가 마크를 알기 전의 일이었어요 The -기 전의 structure where -의 is the possessive particle 'of', corresponds to 'of before' in English. The inclusion of -의 implies that the structure is always followed by a noun.

Accepted Answer

This was before I knew Mark

Front	이것은 내가 마크를 알기 전의 일이었어요
Back	This was before I knew Mark
Notes	The -기 전의 structure where -의 is the possessive particle 'of', corresponds to 'of before' in English. The inclusion of -의 implies that the structure is always followed by a noun.

전의 Structure 의 이것은 내가 마크를 알기 일이었어요