Idiom B1 Informal

Cost a pretty penny

To be very expensive; to cost a large amount of money

Meaning

Cost a pretty penny — To be very expensive; to cost a large amount of money. Here 'pretty' is an old intensifier meaning 'considerable', so a 'pretty penny' is a sizeable sum.

Origin & History

The phrase dates back several centuries in English. The word 'pretty' was once commonly used to mean 'considerable' or 'fairly large', as in 'a pretty sum'. A 'pretty penny' therefore meant not a small coin but a substantial amount of money.

The expression appears in 18th-century writing and has remained popular ever since, even though this older sense of 'pretty' has mostly disappeared from everyday use. Today it survives chiefly in this fixed idiom.

Example Sentences

SentenceContext
That new car must have cost a pretty penny.Expensive purchase
Renovating the kitchen cost us a pretty penny.Home improvement
Tickets for the final cost a pretty penny this year.Events
Her designer handbag clearly cost a pretty penny.Luxury goods
Sending the parcel overseas cost a pretty penny.Shipping
The repairs to the roof cost a pretty penny.Maintenance

How to Use It

This idiom is informal and emphasises that something is expensive, usually with mild surprise or admiration. It typically follows the verb cost, as in cost a pretty penny or must have cost a pretty penny. It works as the object of 'cost' and is not used with other verbs.

Common Mistakes

Mistakes to Avoid

It cost a pretty pennies.

It cost a pretty penny. — The noun stays singular: 'penny'.

It costed a pretty penny.

It cost a pretty penny. — The past tense of 'cost' is 'cost', not 'costed'.

It was a pretty penny to buy.

It cost a pretty penny to buy. — The idiom is normally used with the verb 'cost'.

Similar Idioms

Cost an arm and a leg Cost the earth Pay through the nose Break the bank All Idioms →

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Frequently Asked Questions

What does "Cost a pretty penny" mean?
"Cost a pretty penny" means to be very expensive or to cost a large amount of money. Here 'pretty' is an old intensifier meaning 'considerable', so a 'pretty penny' is a sizeable sum.
Where does the idiom "Cost a pretty penny" come from?
The phrase dates back several centuries. The word 'pretty' once commonly meant 'considerable' or 'fairly large', so a 'pretty penny' meant a substantial amount of money rather than a small coin. It appears in 18th-century writing and has stayed popular ever since.
Can you give an example of "Cost a pretty penny" in a sentence?
Here is an example: "That new car must have cost a pretty penny." — used to say something was very expensive.
Is "Cost a pretty penny" formal or informal?
It is informal. It is common in everyday conversation and casual writing, often expressing mild surprise at a high price, but is best avoided in formal writing.
What CEFR level is "Cost a pretty penny"?
This idiom is typically taught at B1 level. It is an intermediate expression that appears frequently in spoken English and informal writing.
What are common mistakes with "Cost a pretty penny"?
Common mistakes include making 'penny' plural or using 'costed' as the past tense. The correct forms are 'a pretty penny' (singular) and 'cost' (unchanged in the past tense).
What idioms are similar to "Cost a pretty penny"?
Similar idioms include: Cost an arm and a leg, Cost the earth, Pay through the nose. These all mean that something is very expensive.
How do I practise idioms like "Cost a pretty penny"?
LexFizz's Flash Cards and Flip Tiles exercises are great for practising English idioms. Try writing your own example sentences using the idiom in context, and listen for it in films, podcasts, and conversations.
Can "Cost a pretty penny" be used in writing?
Yes, in informal writing, emails, and journalism. Avoid it in formal academic writing unless you are quoting or discussing the idiom itself.
Does "Cost a pretty penny" have the same meaning in British and American English?
Yes, "Cost a pretty penny" is understood in both British and American English with the same meaning: to be very expensive. The idiom is widely recognised across all major varieties of English.