爸爸在上班怎么说英语

To say "dad is at work" in English, you can simply say "Dad is at work." You could also say "My father is at his job," or "My dad is working." It all depends on the context and the level of formality you want to use. If you want to be more specific, you could say something like "Dad is at the office," or "Dad is at his place of employment."