After

Today I modified the diary that my teacher checked yesterday.
I and my friend are the weak-willed persons, so I bet with her.
Since we decided to pay 5$(bucks) each other if we don't write a journal a day.

Before

Today I modified the diary~~,~~ that my teacher checked it yesterday.
And we are the weak will person, so I bet with her.
We decide to pay 5$ each other, that we didn't write a diary for a day.

오늘 난 어제 선생님이 체크해준 영어일기를 수정했다.  
그리고 우리는 의지가 약한 사람이라서 친구와 내기를 했다.  
서로 일기를 쓰지 않는 날에는 벌금을 5불씩 내기로 했다.