Don’t be fooled by ‘in’

These three pairs of words look like they should be opposites, but are they?

We know inflammation looks red and feels hot, like something’s burning.

So, it makes sense that inflammable means something that can catch fire.

But what about flammable?

Doesn’t that look like flames, making us also think something can catch fire?

Yes, it does.

In fact, inflammable and flammable mean the same, even though they look like opposites.

Which is weird, but not unique.

There’s also valuable versus invaluable.

Your colleague’s valuable advice was very important and worth a lot to you as it helped you accurately diagnose your patient’s problem.

Does that mean your supervisor’s invaluable advice was not important?

Actually, invaluable means extremely valuable and your boss’s invaluable advice suggested the best treatment for your patient.

Not opposites either.

Neither is this pair:

Would you like to work in a famous clinic known worldwide for its stellar reputation?

Sure, you would.

How about in an infamous clinic?

No way.

An infamous clinic is also well-known around the world, but for the wrong reasons. It has a negative name, perhaps due to its discredited therapy or eccentric management.

How can you easily remember the quirks of in/flammable, in/valuable and in/famous?

Make your own catchphrases.

See here, here and here for explanations of other common confusions.

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