Let’s pretend you don’t know the answer already. You might well think that active verbs describe actions, especially really energetic actions like hopping, skipping and jumping - the kind of thing that burns up calories fast. In contrast, passive verbs are used (you might think) for things that you suffer passively, like sneezing, dying and (maybe) lying back and thinking of England. The ultimate passive verbs should be suffer and undergo.

But, as you know, that’s all wrong. That’s not what “active” and “passive” mean in grammar, whatever they may mean in ordinary life. They’re technical terms with a couple of thousand years of history behind them, so guessing doesn’t help.

In grammar, it’s all to do with subjects, objects and verbs, and how they combine to describe the situation concerned. The normal arrangement is like this:

* The verb says what happened

* The subject (the noun before the verb) says who did it

* If there is one, the object (the one after the verb) says who or what else was involved. For example: John ate an apple.

subject verb object This means:

* Some eating took place

* John did it

* It involved an apple too The normal arrangement is called “active”. More precisely, the verb is described as being in the “active voice”. (Don’t ask us what “voice” has to do with its ordinary meaning!) “Passivisation” reverses the normal arrangement producing a rather more complicated structure. For example the passive of the earlier example is: An apple was eaten by John.

subject verb-chain modifier

Why are active and passive verbs important? Because they’re related in a very regular way by passivisation. Take a verb - any verb - that has an object, tweak its verb, and, hey presto, you have another verb with exactly the same meaning but a different subject (the old object).

It doesn’t have to be an “activity“verb. There’s nothing active (in the ordinary, non-grammatical sense) about owning a car, admiring Einstein or understanding grammar, and yet these all have their active and passive versions: Most people own cars.

Cars are owned by most people.

Everyone admires Einstein.

Einstein is admired by everyone.

Anyone can understand grammar.

Grammar can be understood by anyone.

What does all this have to do with teaching? First, passivisation is an enormously important resource which almost doubles our vocabulary of verbs. If the active isn’t quite right, maybe the passive will work better. Second, it’s an essential feature in a lot of the texts our students encounter. In science, history, design technology and many non-fiction text-types, passives abound.

The truth is, the passive unnerves a lot of people. They think it’s more complicated than it actually is. So we owe it to our students to help them to see the passiveactive distinction not as a barrier to learning, but as another useful tool for their own understanding and expression.

Richard Hudson is professor of linguistics at University College, London Geoff Barton is headteacher of King Edward VI School, Bury St Edmunds, Suffolk