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。 If the company he works for offers organized German classes, then we can say He sometimes stays at the office after work for his German class. After the class he goes home. Enquiring Mind said: Hi TLN, generally the -ing form tends to sound more idiomatic and https://youtu.be/T0zWXvhEQwo?si=wNc6ihu97ShtIl7u