YOU SAID:

i think my sister is dropping off school because she is failing

INTO JAPANESE

私は彼女が失敗しているので、私の妹は学校を離れていると思う

BACK INTO ENGLISH

I guess my sister is leaving school because she has failed

INTO JAPANESE

彼女は失敗したので私の妹は学校を離れていると思う

BACK INTO ENGLISH

I think that my sister is leaving school because she failed.

INTO JAPANESE

彼女は失敗したので私の妹は学校を離れていると思う。

BACK INTO ENGLISH

I think that my sister is leaving school because she has failed.

INTO JAPANESE

彼女は失敗したので私の妹は学校を離れていると思う。

BACK INTO ENGLISH

I think that my sister is leaving school because she has failed.