YOU SAID:

I'm going out to dinner

INTO JAPANESE

私は夕食に出かけるをつもり

BACK INTO ENGLISH

I am planning to go out for dinner

INTO JAPANESE

夕食のため外出するつもりです。

BACK INTO ENGLISH

I am going to go out for dinner.

INTO JAPANESE

私は夕食に出かけるつもりです。

BACK INTO ENGLISH

I am going to go out to dinner.

INTO JAPANESE

私は夕食に出かけるつもり。

BACK INTO ENGLISH

I'm going to go out to dinner.

INTO JAPANESE

私は夕食に出かけるつもり。

BACK INTO ENGLISH

I'm going to go out to dinner.