All of a sudden vs. All of the sudden

All of a sudden

/ɔ:l ɔv ə ˈsʌdən/

Happening unexpectedly or without warning

Examples:

All of a sudden, the skies opened and it began to pour.She was calm, but then all of a sudden burst into tears.The peaceful lake erupted all of a sudden into thunderous waves.

Synonyms:

unexpectedlyabruptlysuddenlyunanticipatedly

Antonyms:

predictably

All of the sudden

/ɔːl əv ðə ˈsʌd.ən/

Unexpectedly or without warning.

Examples:

All of the sudden, the lights went out.We were walking when all of the sudden it started raining.She was fine, then all of the sudden she fainted.

Synonyms:

suddenlyabruptlyunexpectedlyinstantaneouslyimmediately

Antonyms:

expectedlygradually

Ways to tell them apart:

• "All of a sudden" is the standard phrase used in English, which dates back several centuries.
• "All of the sudden" is often considered incorrect in formal writing, even though it is used colloquially.
• Remember that the word "a" in the phrase "all of a sudden" is essential, marking a more recognized usage.
• You can think of "all of a sudden" as meaning "suddenly" or "unexpectedly".
• The confusion arises because both phrases are used, but only "all of a sudden" is widely accepted in standard English.