How many classes do you have today?

今天你们有几节课?。

youdao

How many classes have you missed so far?

到目前为止，你缺了多少课？

youdao

How many classes are there in Grade One?

一年级有几个班？

youdao

How many hours do the students take classes usually?

学生们通常上几小时的课？

很好奇住宿生活 - SpeakingMax英语口语达人

When the farmers were unable to figure out how to use the software, many of them ended up paying for classes that taught them how to use it.

FORBES: FarmLogs Is Going To Change The Way That Farmers Manage Their Business

On social media, many Brazilians reacted to the news saying that the country's middle classes would have to learn how to live without house maids, as has already happened in many developed countries.

BBC: Domestic workers to get equal rights in Brazil