English · Greetings & Phrases
all of a sudden
/ɔːl ʌv ə ˈsʌdn/
[/ɔːl ʌv ə ˈsʌdn/]
suddenly
Intermediatephrase
Definition
Happening quickly and unexpectedly, without warning.
Example
All of a sudden, the lights went out.
All of a sudden, the lights went out.
Etymology
An expansion of 'sudden', with 'all of a' adding emphasis; used since the 1600s.
How & Where It’s Used
Common in storytelling and casual speech.
Literary Heritage
The phrase appears in Shakespeare's 'The Taming of the Shrew'.