YOU SAID:
My friend is terrible at answering my Facebook messages.
INTO JAPANESE
私の友人は私のFacebookのメッセージに答えるのがひどい。
BACK INTO ENGLISH
My friend is terrible to answer my Facebook message.
INTO JAPANESE
私の友人は私のFacebookメッセージに答えるのがひどいです。
BACK INTO ENGLISH
My friend is terrible to answer my Facebook message.
You've done this before, haven't you.