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 correct and widely accepted phrase.
• Think of a in the phrase as a for abrupt, emphasizing the abrupt shifting nature.
• All of the sudden is considered non-standard and is often a mishearing of the correct phrase.
• Remember sudden as the focal point of something happening without warning.
• Native speakers widely accept and use all of a sudden in both formal and informal contexts.