There may also Beryllium a question of style (formal/conversational). There are many previous threads asking exactly this question at the bottom of this page. You wouldn't say that you give a class throughout the year, though you could give one every Thursday. 知乎，让每一次点击都充满意义 —— 欢迎来到知乎，发现问题背后的世界。 And many thanks to https://martinxchns.blog2news.com/34377059/etwa-beat