I sit the children down and I tell them that I’m very nosey, and that I love listening to conversations on buses and trains, in the park, or on the phone. The trouble is, I tell them, you can usually only hear one side of the conversation and you have to imagine what the other person is saying.

Then we start making some up. Things like: He said: “I’ve got a rash, dear.”

She said: “Whereabouts?” He said: “On my knee.”

She said: “It’ll go.”

We do dozens and dozens of these - the rule is they have to be short, only four lines long - and we act them out, putting on accents and so on. by then the children are gripped, and they want to go on and on.

Then I say “Okay, you choose the situation”, and they’ll decide to do a bus stop, or a fish and chip shop queue, or McDonald’s. They write the dialogues individually, then they choose someone to perform them with, and it all becomes an interesting lesson in class dynamics. You never can tell who they are going to choose to perform with. It often is the least likely classmate.

They soon become desperate to add one more line. “Please,” they say, “oh, please! Just one more!” So, acting very reluctant, I finally say, “All right, you’ve persuaded me. One more line.” A cheer goes up, and the pieces get longer and longer until by the end you’ve practically got them to write and perform a full play, complete with sound effects.

The ones they really like, and really get into, are the ones with a touch of anger. The ones that hint at trouble. Like if a child in the supermarket knocks the salad cream over and it splatters over the floor and Mum’s being as nice as anything in the shop, but everyone knows that there’s going to be trouble later when she gets the child outside.

They love that moment’s pause before the anger, and the fact that they recognise what’s coming. Also, of course, they love the fact that they can explore these feelings in a controlled situation.

They particularly like the kind of conversations older brothers or sisters have on the phone. They obviously listen to a lot of these because they seem very familiar with the tensions involved in conducting your love life over the phone, and the kind of things that get said in a crisis.

It’s also fascinating seeing what sort of things they associate with a particular situation. “At the dentist” is always fairly soothing. The dentist is nice and gentle and reassuring, and says things like “this won’t hurt at all . . .” But “At the doctor” has an edge to it. The doctor is always making clear that he or she is very busy, and that the patient should just take the medicine and get out. They have a real picture of GPs being short of time and anxious to get on with it.

The ones that aren’t so successful are “On the bus” and “On the train” because children don’t seem to go on buses or trains much any more. They go by car. I recently taught 18 Year 6s, and only nine had ever been on a train, and only five of these had been on one in the past 12 months.

I thought I’d thought this lesson up for myself, but I then discovered a book of poetry, published by Puffin, called He Said, She Said, They Said by Anne Harvey, so I usually finish off the lesson by reading some extracts from this.

Les Kemp is head of Moulsham County Junior School, Chelmsford, Essex