YOU SAID:

i was studying when it started to rain in school in the bus yesterday

INTO JAPANESE

昨日バスの中で学校で雨が降り始めた時勉強していた

BACK INTO ENGLISH

I was studying when it started to rain at school yesterday on the bus

INTO JAPANESE

昨日バスで学校で雨が降り始めた時勉強していた

BACK INTO ENGLISH

I was studying when it started to rain at school yesterday on the bus