上小学四年级用英文怎么说

"上小学四年级" 用英语说是 "in the fourth grade of elementary school"。

其中 "in" 是介词，表示在某个地点或状态中。"the" 是定冠词，表示特指某个具体的年级。 "fourth" 是第四个的意思。 "grade" 是年级的意思。 "elementary school" 是小学的意思。

例句：

I was in the fourth grade of elementary school when I first learned how to read. (我上小学四年级的时候第一次学会了读书。)
My sister is in the fourth grade of elementary school now. (我的姐姐现在上小学四年级。)
I remember my teacher in the fourth grade of elementary school. (我还记得我小学四年级的老师。)