YOU SAID:

if you sit on a red chair, your brother will come home late

INTO JAPANESE

あなたが赤い椅子に座れば、あなたの兄弟は遅く帰宅するでしょう

BACK INTO ENGLISH

If you sit in a red chair, your brother will come home late.

INTO JAPANESE

赤い椅子に座れば、お兄さんは遅く帰宅します。

BACK INTO ENGLISH

If you sit in a red chair, your brother will come home late.