Names for the number 0 in English call the first decade of the 21st century, as "00s" is not usually pronounced as a word. Apart from side stepping the issue and calling the decade the "two-thousands" (2000s) there is no agreed wording, although in Britain and some other countries "noughties" was also used. There is a need to maintain an explicit distinction between digit zero and letter O, which, because they are both usually represented graphically in English orthography (and indeed most orthographies using Latin script and Arabic numerals) with a simple circle or oval, have a centuries-long history of being frequently conflated. However, in spoken English,
Old English phonology fronting of the open vowel to in certain cases. It also underwent vowel shifts that were not shared with Frisian: smoothing, diphthong height harmonization, and breaking. Diphthong height harmonization and breaking resulted in the unique Old English diphthongs , , , . Palatalization yielded some Modern English word-pairs in which one word has a velar and the other has a palatal or postalveolar. Some of these were inherited from Old English ("drink" and "drench", "day" and "dawn"), while others have an unpalatalized form loaned from Old Norse ( and ). Old English had four major dialect groups: Kentish, West Saxon,