This is how it works:

Nurse Myra is scheduled to do English lessons on Monday night. Tonight, there is some question as to whether the classes are on.

The interpreters are Mr Thinh and Miss Linh.

On quizzing Mr Thinh early in the day, yes, the classes are definitely on. Later Miss Linh says that Mr Thinh has said that the classes are not on any longer. On talking further with Miss Linh, however, it seems that she is not really sure if the classes are on. Or in fact, if Mr Thinh actually said the classes are not on. Mr Thinh, on the telephone, says that the classes are on.

We think.

Later, we see Miss Linh, who says that the classes are not on. Is she sure?

Yes, she is sure.

That the classes are not on?

No.

That they’re on?

Yes.

She’s sure they’re on?

No.

Are the classes on?

Yes, Mr Thinh says the classes are not on.

On the telephone, Mr Thinh says the classes are on.

Definitely?

Yes.

We think.

So we walk around to the classrooms. It looks deserted. The gates are closed and padlocked. But there are lights on inside. Nurse Myra reaches through and is able to undo one padlock. We open the gate and walk inside.

From somewhere two guard dogs appear, snarling and barking.

Definitely not on.