YOU SAID:

I swear I just want to be friends with him

INTO JAPANESE

私はただ彼と友達になりたいと誓う

BACK INTO ENGLISH

I just swear that I want to make friends with him.

INTO JAPANESE

私は彼と友達になりたいと誓うだけです。

BACK INTO ENGLISH

I just swear that I want to make friends with him.