小学同学用英语可以称为"elementary school classmate"。

这个词的来源是由两个词组合而成的："elementary school"和"classmate"。"elementary school"指的是小学，而"classmate"则指的是同班同学。

一些英文例句和中文翻译如下：

I used to play with my elementary school classmate at the park after school.

我过去常常在放学后和我小学同学在公园玩。

My elementary school classmate and I have been friends for over 10 years.

我和我的小学同学已经是朋友10多年了。

I invited my elementary school classmate to my birthday party.

我邀请了我的小学同学参加我的生日聚会。