I was with a mate.

我和一个朋友在一起。

《牛津词典》

She and her mate had just returned on the day I went to work and the old couple welcomed them happily.

我上班的那天，她和她的伴侣刚回来，这对老夫妇很高兴地欢迎他们。

youdao

I hope you are my soul mate and we match each other!

我希望你就是我灵魂的伴侣，我们就可以互相依偎照顾！

youdao

Well, I tell you what, Gilligan. The day that you area shrimp boat captain, I will come and beyour first mate.

VOA: standard.other

and... I told you if you were evera shrimp boat captain, that I'd be your first mate.

VOA: standard.other

"Look,I don't know mate maybe it's something in the water back home;

VOA: standard.2010.04.30

Michael: I can't get out mate, I'm stuck in the back because there's the caravan at the side of the house and there's smoke all downstairs.

BBC: Transcript of 999 Derby fire call

Michael: I've got a ladder here mate and I've smashed the window.

BBC: Transcript of 999 Derby fire call

It was a big operation and I actually worked for his running mate, so I only spoke with Mitt a handful of times.

FORBES: Bullying and Mitt Romney's Empathy Problem