YOU SAID:

We could throw a party

INTO JAPANESE

私たちはパーティーを開くことができました

BACK INTO ENGLISH

We were able to have a party

INTO JAPANESE

パーティーができました

BACK INTO ENGLISH

I got a party.

INTO JAPANESE

パーティーをしました。

BACK INTO ENGLISH

I made a party.

INTO JAPANESE

私はパーティーを作りました。

BACK INTO ENGLISH

I made a party.