was/were together
昨日一緒にいた、あのカッコいい人は誰なの？
Who was that good-looking person you were with yesterday?
昨日一緒にいた女の人誰？
Who was the woman you were with yesterday?
私達が一緒にいた事は誰も知らない方がいい
It’s better if no one knows that we were together.
— ピエロがお前を嘲笑う (2014)
私たちは一緒にいた。
We were together.