YOU SAID:

I still regret it to this day that I accepted his friend request

INTO JAPANESE

私は彼の友人の要求を受け入れたことを今でも残念に思っています

BACK INTO ENGLISH

I am still sorry that I accepted his friend's request

INTO JAPANESE

私はまだ彼の友人の要求を受け入れたのが残念です

BACK INTO ENGLISH

I'm still sorry I accepted his friend's request

INTO JAPANESE

私は彼の友人の要求を受け入れた

BACK INTO ENGLISH

I accepted the request of his friend

INTO JAPANESE

私は彼の友人の要求を受け入れました

BACK INTO ENGLISH

I accepted his friend's request

INTO JAPANESE

私は彼の友人の要求を受け入れました

BACK INTO ENGLISH

I accepted his friend's request