"Sixth grade, class one" 用英语表达为 "Grade six, class one"。
来源：“Sixth grade” 指六年级，“class one” 指一班。
例句：
"I'm in Grade six, class one." (我在六年级一班。)
"Which class are you in? I'm in Grade six, class one." (你在哪一班？我在六年级一班。)
"My pttle brother is in Grade six, class one." (我弟弟在六年级一班。)