And hello, I'm Rob.

You're looking pleased with yourself, Rob.

Oh, I am. I've just booked these dirt cheap – I mean really cheap – flights to Ibiza!

Wonderful!

Look at the price - 20 pounds return!

That means extra money to spend on food, drink and partying.

Let's have a look… hold on. The basic price is 20 pounds, but look at the tax you have to pay on top. One hundred pounds!

Eh? Let me see. You're right.

Grrr, I hate paying tax.

I guess you could say it's a necessary evil.

Hmm, you could say that – if you mean it's something bad that can't be avoided, and you have to accept it in order to achieve a good result.

That's exactly what I meant, Rob.

If it can't be avoided, like paying tax on a plane ticket, then it's a necessary evil.

Let's hear some examples, shall we?

For me, exams are a necessary evil – you have to do them to get a place at university.

Sitting in traffic for hours is a necessary evil if I want to drive to the seaside on a public holiday!

I hate running, but having to exercise is a necessary evil if I want to stay fit and healthy.

This is The English We Speak from BBC Learning English and we're finding out about the phrase 'a necessary evil'.

It describes something that you have to accept in order to achieve something else.

And Rob, that tax on your plane ticket is unavoidable – so not so cheap now, is it?

No. Less money for eating, drinking and partying.

Can you get a refund? Stay at home and eat, drink and party?

I could but if I stayed at home, there's another necessary evil I have to deal with.

What's that?

I'll have to spend more time with you.

Hmm! What time is your flight exactly?

Did I say something wrong?

Bye.

Bye.