YOU SAID:

I am going to a shop tomorrow

INTO JAPANESE

明日お店に行く予定です。

BACK INTO ENGLISH

I'm going to the shop tomorrow.

INTO JAPANESE

私は明日、買い物をするつもりです。

BACK INTO ENGLISH

I'm going tomorrow to buy.

INTO JAPANESE

私は明日購入するつもりです。

BACK INTO ENGLISH

I'm going to buy it tomorrow.

INTO JAPANESE

私は明日それを購入するつもりです。

BACK INTO ENGLISH

I'm going to buy it tomorrow.