YOU SAID:
I'm not sure if I can go to the party with you
INTO JAPANESE
あなたと一緒にパーティーに行けるかどうかわかりません
BACK INTO ENGLISH
I don't know if I can go to the party with you
INTO JAPANESE
あなたと一緒にパーティーに行けるかどうかわかりません
BACK INTO ENGLISH
I don't know if I can go to the party with you
You've done this before, haven't you.