Anna: Now we have a question from Shazad. Shazad has a problem with the following sentence: "work hard lest you should fail in your examination". Now Shazad wants to know, can 'lest' in this sentence be used without the support of the word 'should'. Well, Martin, what do you think about that - can 'lest' be used without the support of 'should'?

Martin: Yes, it can. And I think before I say a little bit about that, we ought to look at what lest means and when we use it. That's lest: l-e-s(for sugar)-t. And I'm saying that, and I'm making a bit of a meal of it, because I think a lot of our listeners won't have come across it; it's a very rare word.

Anna: It's quite old-fashioned, isn't it?

Martin: And it's very old fashioned. Of course, most people here in Britain know it, because we see it written very often in the same place - and that's on war memorials, on statues, which have been put up so that we remember people who died in wars; and what's very often written on these statues is "lest we forget"! Now, what lest means is "so that we don't" or "so that you don't". It's a warning. It's introducing a danger to be avoided. And this example that Shazad has sent in, "work hard lest you should fail your examination" is a good example - lest introduces the danger of things to be avoided: if you don't work hard, you will fail your examination.

Listen to some other examples: we often use it after a command, so "work hard lest you fail your exam", "dress up warmly (wear warm clothes) lest you catch cold". We can use it without a command; we might talk about something we did in the past, so we might say "I worked really hard, lest I failed my exam".

What we do need to remember though is that it is a very, very formal and old-fashioned word and if you use it when you're talking, you're going to sound rather strange. It's a word which we see written - it's not a word that is used in conversation. And my advice is to remember it, because you will see it written; but only use it if you really want to impress somebody in a very, very formal situation.

Anna: And the other part of the question from Shazad is, can lest be used without the support of the word should? What do you think about that?

Martin: Yes. And it normally is used without should. In Shazad's example, 'lest you should fail your examination', that use of should of course has a completely different meaning from the usual meaning of should.

We usually think of should in terms of an obligation: something you have to do. And here, it doesn't mean that - here, the meaning introduces a conditional that suggests that this is a possibility, but not a strong possibility. It is not necessary. We usually do leave it out. And, the interesting thing is, that when we do leave it out, the word that is left there is an infinitive – which means, that if we're using "he", we don't say "he must work hard, lest he fails the examination"; we say "he must work hard, lest he fail the examination". And that's a curious and interesting little bit of English.

Anna: So in this example, work hard lest you fail your examination - that's how it would read?

Martin: ...is fine, yes.

Anna: OK - that's great, thanks very much.

Martin: A very interesting question.