Continuing from yesterday’s post, there is one more usage for はい(ha-i) that you should be aware of- the inquisitive version. This means you add a question mark to the end. You have to say it with a rising tone, just like when asking a question in English.
This means “Excuse me?”, “I’m sorry?”, or “Come again?”. It can be used in situations where the listener could not hear exactly what the speaker was saying, or the listener is baffled or in disbelief at what the speaker said. For example: