The word “off” looks small, but it carries an impressive amount of meaning. It can describe a light that is not shining, a person who is away from work, a machine that has stopped, or a feeling that something is not quite right. Its meaning changes with the situation, which is why learners of English often find it more difficult than its size suggests.
The most familiar use appears in everyday instructions. When someone says, “Turn the TV off,” they mean to stop its operation. “The lights are off” tells us that the room is dark, while “The computer is off” means it is no longer running. In these examples, “off” often works as the opposite of “on,” and it is closely connected with switches, devices, and energy.
The word also describes movement away from a place or surface. A cat jumps off the table. A passenger gets off the bus. A cup falls off a shelf. In each sentence, “off” suggests separation from something. This meaning becomes less physical in expressions such as “The meeting is off,” which means the meeting has been canceled, or “The deal is off,” meaning an agreement will not continue.
Schedules provide another common use. If an employee says, “I’m off tomorrow,” they usually mean they do not have to work. Someone may also say, “I’m off to the store,” meaning they are leaving for the store. The same word can therefore describe both a break from responsibility and the beginning of a journey.
“Off” can also refer to food, behavior, and emotions. If milk smells off, it may have spoiled. If a person seems off, they may be unusually quiet, tired, uncomfortable, or worried. This does not always identify the exact problem; it simply communicates that something feels different from normal. A friend might notice that you are not talking much and ask, “Are you feeling okay? You seem a little off.”
There are also expressions in which “off” has a more abstract meaning. To take time off means to rest away from work or school. To show off means to behave in a way designed to attract admiration. To put someone off means to discourage them or make them lose interest. If an alarm goes off, it starts making noise, which can seem confusing because “off” here does not mean silence. The phrase developed from the idea of an action being triggered or released.
In conversation, “off” often adds a sense of distance or interruption. Someone may say, “The train is off,” meaning it has departed, or “I’d better be off,” meaning it is time to leave. In sports and performances, an event can be “off,” while a person can be “off their game” when they are performing below their usual standard.
Learning “off” is less about memorizing one definition and more about noticing the words around it. “Turn off,” “get off,” “take off,” “call off,” and “go off” each form a different expression. The surrounding verb and situation usually reveal the intended meaning. That flexibility is what makes “off” so useful—and occasionally so tricky—in everyday English.