YOU SAID:

this happen if this happens then do that thing.

INTO JAPANESE

これが起こった場合、これが起こり、そのことを行います。

BACK INTO ENGLISH

If this happens, it happens and it does it.

INTO JAPANESE

これが起こった場合、それは起こり、それを行います。

BACK INTO ENGLISH

If this happens, it happens and it does it.