YOU SAID:
i would like to invite everyone to my birthday party in fifty years
INTO JAPANESE
50年後の誕生日パーティーにみんなを招待したいです
BACK INTO ENGLISH
I want to invite everyone to a birthday party 50 years from now
INTO JAPANESE
50年後の誕生日会にみんなを招待したい
BACK INTO ENGLISH
I want to invite everyone to a birthday party 50 years from now
That didn't even make that much sense in English.