Out of the blue means suddenly and unexpectedly, with no warning at all. The blue here is the clear sky, so the image is of something appearing from a cloudless sky. People use it about a call, a piece of news or an offer that nobody expected. The expression is conversational; in an IELTS essay, unexpectedly is a better choice.
When would you say out of the blue?
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call/text/appear + out of the blue; Out of the blue, + clause; come + (completely) out of the blue
- An old school friend called me out of the blue and invited me to his wedding.
- Out of the blue, my manager offered me a place on the new project in London.
- The storm came out of the blue, so we spent our beach day in a café.
What changed
First versionLast week my old boss wrote to me from the blue and offered me a job.
RevisionLast week my old boss wrote to me out of the blue and offered me a job.
Out of and from can both describe where something comes from, so from the blue is an easy slip. But the words in this idiom are fixed, and only out of the blue is used. The similar expression a bolt from the blue, which really does use from, can add to the confusion.
A bolt from the blue names the unexpected event itself, a complete shock: Her resignation was a bolt from the blue. Out of the blue describes how something happened: The news came out of the blue.
Your turn
Nobody knew she was unhappy, so her decision to leave the company came completely ___.
Show the answer
out of the blue — Nobody saw her decision coming, so it was unexpected: out of the blue. Once in a blue moon means “very rarely” and describes something that happens now and then, not a single sudden event.
Think of an unexpected call, message or email. Write who contacted you and what they offered you.
Last spring a former colleague messaged me out of the blue and offered me a part-time job at her design studio.
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