Are you free to join us for dinner tomorrow?
明晚有空來我們家吃晚飯嗎?
You are inviting me to your house?
你是在邀請我去你家嗎?
Sure.
當然。
重點講解:
Do you have free time to have dinner with us tomorrow?
Are you free to join us for dinner tomorrow?
Be free指是否有空,詢問對方是否有空時,可以不用have free time,而直接用Are you free to do sth.?