All of a Sudden or All of the Sudden | Which is Correct?

The correct phrase is all of a sudden, which means “quickly,” “unexpectedly,” or “at once” (e.g., “All of a sudden, the dog jumped all over me”). “All of the sudden” is an increasingly common error, although there is no grammatical rule that explains why “a sudden” is preferred over “the sudden.”

Examples: All of a sudden or all of the sudden in a sentence
  • And then all of a sudden, everyone jumped out and screamed, “Surprise!”
  • And then all of the sudden, everyone jumped out and screamed, “Surprise!”
  • All of a sudden, the lights went out.
  • All of the sudden, the lights went out.

All of a sudden

“All of a sudden” is an idiom that means “suddenly.” In other words, it functions as an adverbial phrase to describe something as happening “quickly and unexpectedly.” For example, if someone says, “All of a sudden, I was really scared,” that means they got frightened very fast and probably didn’t expect to.

The phrase “all of a sudden” can be found at the beginning, middle, or end of a sentence. When it is used at the start of a sentence, it is typically followed by a comma.

Examples: All of a sudden in a sentence
All of a sudden, it started pouring just as we were preparing the picnic.

There was a loud, creaking sound, and then all of a sudden, the cabinets fell.

She was happy at first, but then she got worried all of a sudden.

“On the sudden” is an archaic variant of this phrase that is no longer used.

Frequently asked questions about all of a sudden or all of the sudden

What does all the sudden mean?

All the sudden is an incorrect variant of the idiomall of a sudden,” which describes something as happening “quickly and unexpectedly” (e.g., “All of a sudden, the table collapsed”).

Our sentence rephraser can help you vary your writing and express your intended meaning.

Is suddenly an adverb?

Yes, suddenly is an adverb that describes something as “abrupt and unexpected” (e.g., “Suddenly, it got really quiet”).

All of a sudden” is an idiom that is synonymous with the word “suddenly” (e.g., “All of a sudden, everyone cheered”).

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Gina Rancaño, BA

Gina holds a Bachelor of Arts in English, as well as a certificate in professional and public writing from Florida International University. When she’s not writing, she spends her time reading.