YOU SAID:
I am having a party tonight.
INTO JAPANESE
今夜はパーティーをしています。
BACK INTO ENGLISH
I'm having a party tonight.
INTO JAPANESE
今夜はパーティーをします。
BACK INTO ENGLISH
We're having a party tonight.
INTO JAPANESE
今夜はパーティーがあります。
BACK INTO ENGLISH
We have a party tonight.
INTO JAPANESE
今夜はパーティーがあります。
BACK INTO ENGLISH
We have a party tonight.
Okay, I get it, you like Translation Party.