YOU SAID:

I went to a cool party last morning

INTO JAPANESE

私は昨晩クールなパーティーに行きました

BACK INTO ENGLISH

I went to a cool party last night.

INTO JAPANESE

私達は昨夜パーティーをした。

BACK INTO ENGLISH

We had a party last night.

INTO JAPANESE

私達は昨夜パーティーをした。

BACK INTO ENGLISH

We had a party last night.