"How are you doing?" is the short and simple way to ask "你好吗" in English. It's a common greeting used to inquire about someone's well-being or mood. The phrase is versatile and can be used in various contexts, such as a casual conversation with friends or a professional email to colleagues.
In addition to asking about someone's physical health, "how are you doing?" can also be used to show interest in their emotional state. For example, if you know someone who has recently gone through a difficult time, you might ask "how are you doing?" as a way to offer support and check in on their well-being.
Overall, "how are you doing?" is a friendly and polite way to start a conversation or express concern for someone's happiness. It's a common phrase in English that is easy to use and can help build connections between people.