all of a sudden

Idioms  

1. Entirely without warning, abruptly, as in All of a sudden the lights went out. In Shakespeare's day the common phrase was of a sudden, the word all being added in the late 1600s. Also see all at once, def. 2.

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Example Sentences

“I came back and all of a sudden they knew every word to the songs,” she says with disbelief.

From Los Angeles Times • Apr. 29, 2026

"You have these peptides that could have a great biological response, but if that biological response only lasts minutes, then all of a sudden you don't have a good therapeutic," Eastman said.

From Science Daily • Apr. 28, 2026

“You might all of a sudden find yourself in suburbia and there is no one that you know or who looks like you,” she said.

From MarketWatch • Apr. 23, 2026

“It’s like taking a piece of fabric and pulling it and all of a sudden everything starts to unfold,” Chinitz said.

From The Wall Street Journal • Apr. 19, 2026

Riemann merged projective geometry with the complex numbers, and all of a sudden lines became circles, circles became lines, and zero and infinity became the poles on a globe full of numbers.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife

Related Words

• precipitously
• suddenly
• unexpectedly