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 well, and was best considered an allophone of , occurring only after a nasal or when geminated. But after became word-initially in Old English, it makes sense to consider the stop the basic form and the fricative the allophone. The evidence for the allophone after front vowels is indirect, as it is not indicated in the orthography. Nevertheless, the fact that there was historically a fronting of to and of to after front vowels makes it very likely. Moreover, in late Middle English, sometimes became (e.g. "tough", "cough"), but only after back vowels, never after front vowels. This is explained