YOU SAID:
友達が明日家に遊びに来る
INTO JAPANESE
友達が明日家に遊びに来る
BACK INTO ENGLISH
my friend is coming to my house tomorrow
INTO JAPANESE
私の友達は明日私の家に来る
BACK INTO ENGLISH
my friend will come to my house tomorrow
INTO JAPANESE
私の友達は明日私の家に来るでしょう
BACK INTO ENGLISH
my friend will come to my house tomorrow
That didn't even make that much sense in English.