YOU SAID:

I am going to watch a movie with my family tomorrow.

INTO JAPANESE

私は明日家族と映画を見るつもりです。

BACK INTO ENGLISH

I am planning to see a movie with my family tomorrow.

INTO JAPANESE

私は明日家族と映画を見る予定です。

BACK INTO ENGLISH

I will see a movie with my family tomorrow.

INTO JAPANESE

私は明日家族と映画を見るでしょう。

BACK INTO ENGLISH

I will see a movie with my family tomorrow.