All of a Sudden or All of the Sudden?
All of a sudden is an idiom that is a more poetic way of saying “suddenly.” A common (типичный) mistake to make, especially for English learners, is to write all the sudden or all of the sudden. On a sudden is a historic but outmoded (устаревший) variant. Currently, all of a sudden is the only accepted usage (общепринятое употребление). Although all of the sudden has been used in centuries past.
