Cách sử dụng
The word 'certain' means something which is definite or sure. It is often used when we are talking about one specific thing, rather than something general. For example, you might say "I am certain that I left my keys on the kitchen counter" to indicate that you are absolutely sure that your keys are there. Similarly, you might use the word 'certain' when you want to emphasize that something is true or accurate, such as "I am certain that this is the correct answer." Overall, 'certain' is a useful word to use when you want to be very clear and specific about something, and to indicate that you are very sure of what you are saying.