I'm going to see an old schoolmate of mine.
我去見一個老校友。
My father still keeps in touch with his old schoolmate.
我父親仍和他的老同學保持聯系。
He started the magazine with a schoolmate
他和一個同學創辦了那份雜志。
On my graduate student's time, an schoolmate's paper discussed this topic.
我上研究生的時候一個同學論文就是做的這個題目。
10 years after graduation, he could hardly recognize his old schoolmate.
畢業10年后，他幾乎認不出他以前的同學了。