Cách sử dụng
'Useful' is an adjective that describes something that is helpful or beneficial. You can use the word 'useful' to describe things that are helpful in everyday life, such as a dictionary, a map, or a calculator. You can also use it to describe skills or knowledge that are helpful, such as learning a new language or how to fix a car. When you want to say that something is helpful or beneficial, you can say "it's useful." Examples: A flashlight is useful when the power goes out. Studying English is useful for travel and communication.