Cách sử dụng
The expression "off the top of your head" means to say something without thinking too much about it or without having any preparation or research. It is used to describe a response that is given quickly based on one's immediate knowledge or opinion, rather than being carefully thought out or researched. For example, if someone asks you a question and you don't know the exact answer, but you have some general idea, you may say "Off the top of my head, I think the answer is...". This expression is often used in casual conversations, but it's not appropriate in formal or professional settings.