Word Choice: Quick vs. Fast

Whoosh! Zoom! Wheee! We have a need for speed today, so we’re focusing on the words ‘quick’ and ‘fast’. Both terms are related to rapidity, but there is a subtle difference between them many people overlook. So join us for a speedy look at how to use these words correctly.

Quick (Speedily or in a Short Time)

We can use the adjective ‘quick’ to refer to something that happens at speed or in a short amount of time. The key in both cases is that ‘quick’ implies brevity of action. For instance:

John was always quick to respond.

I’ll give your essay a quick look before you hand it in.

These uses are similar, but the second doesn’t necessarily require speed. You could have a ‘quick nap’, for example, which would be short but static.

The adverbial form of this word is ‘quickly’. For example, we might say:

She moved quickly to catch the falling vase.

Many people now also use ‘quick’ as an adverb. This is fine in everyday conversation as long as you are clear about your meaning. But you should always use ‘quick’ with nouns and ‘quickly’ with verbs in formal writing.

Fast (At High Speed)

‘Fast’ is another adjective that we use when something happens at speed. This can be a movement, a reaction, or the rate at which something happens, such as a process. For instance, we could use it as follows:

Sherry was faster to respond than Tim.

The fast pace of change took some by surprise.

In these cases, then, ‘fast’ and ‘quick’ are largely interchangeable.

The main difference between these words is that ‘fast’ does not always imply that something takes a short amount of time. For instance, we can also use it to describe something that can move quickly for long periods:

I’ve always loved fast cars.

In this case, ‘fast’ refers to the potential for sustained speed. It would be unusual to say that a car is ‘quick’ (although a journey in a car could be quick).

One exception to this general rule is ‘fast food’, which is so called because it is made quickly. It does not, however, move fast unless you throw it across the room, which is widely considered impolite.

On top of this, we can use ‘fast’ as an adverb when describing an action:

You always drive too fast.

Here, again, the emphasis is on sustained speed more than brevity of action.

Finally, ‘fast’ has some other meanings unrelated to speed, such as ‘hard to move’ or ‘abstain from food’. However, these are harder to confuse with the word ‘quick’, so it should be easy to avoid errors.

Summary: Quick or Fast?

These words are often interchangeable when referring to something that happens at speed. But ‘quick’ and ‘fast’ also have some distinct uses:

• Quick usually implies brevity (i.e. that something happens in a short time).
• Fast does not necessarily imply brevity (i.e. something can be ‘fast’ and occur over a long period). In addition, ‘fast’ can imply a capacity for speed (e.g. we might identify something as a ‘fast car’ even when it is not moving).

So, for example, we offer a fast proofreading service. This refers to the rate at which we work, even if it may still take a while to finish checking a longer document. But if someone offers to give your document a quick look, this usually implies spending only a short time checking it.