# How does “about” change a sentence?

I really wonder, the following sentences relate to each other? Why can we emphasize about in a sentence?

The restaurant closes in about 5 minutes.

The restaurant closes in 5 minutes.

In the first sentence, about conveys that the amount of time is approximate. From Collins:

approximately; near in number, time, degree, etc ⇒ "about 50 years old"

In the second sentence, there is no such indication. The number may be exact, but it may also be an approximation.

If you want to make it clear that it's not an approximation, you can indicate that it's an exact number by saying "exactly five minutes", "five minutes flat", "five minutes and zero seconds", or something similar.

• Just to be pedantic: All measurements of time and distance are inherently approximations of more or less accuracy. If you say, "It was EXACTLY 5 minutes", I could quibble, "Are you sure it was not 5 minutes and 1 second? 5 minutes and .001 seconds?" etc. Scientists talk about the precision of measurements, accurate to how many digits, etc, when it really matters. So the difference between "5 minutes" and "about 5 minutes" is really one of how imprecise the measurement is. A count can be exact. You can say with strict literal accuracy, "There were exactly 25 people in the room." – Jay Feb 18 '14 at 19:14
• @jay Since this site is about learning a language, and not about scientific measurments, I'd say that the given answer is exactly what the OP needed. – TecBrat Feb 18 '14 at 19:51
• A similar usage to understand is "Are you about ready" in which "about" means "nearly" and the sarcastic "It's about time!" which really implies "It is well past time!" – TecBrat Feb 18 '14 at 19:55

"About" in this context demonstrates uncertainty.

In the second sentence, the restaurant is closing in exactly 5 minutes.

In the first, the restaurant is closing soon, but it may not be exactly 5 minutes from now. It could be a little sooner or a little later.

• True. In common usage, it's usually understood that a sentence like this would be an approximation. But as stated, the literal meaning is an exact time. In cases referring to things like train departures, the window of approximation is much narrower. If the train leaves in 3 minutes, there may only be 20-30 seconds of leeway, for example. – Roger Feb 18 '14 at 16:23