Two is most commonly adeterminer used withplural countable nouns, as intwo days orI'll take these two.[1]Two is anoun when it refers to the number two as intwo plus two is four.
Etymology oftwo
The wordtwo is derived from theOld English wordstwā (feminine),tū (neuter), andtwēġen (masculine, which survives today in the formtwain).[2]
The pronunciation/tuː/, like that ofwho is due to thelabialization of the vowel by thew, which then disappeared before the related sound. The successive stages of pronunciation for the Old Englishtwā would thus be/twɑː/,/twɔː/,/twoː/,/twuː/, and finally/tuː/.[2]
The digit used in the modern Western world to represent the number 2 traces its roots back to the IndicBrahmic script, where "2" was written as two horizontal lines. The modernChinese andJapanese languages (and KoreanHanja) still use this method. TheGupta script rotated the two lines 45 degrees, making them diagonal. The top line was sometimes also shortened and had its bottom end curve towards the center of the bottom line. In theNagari script, the top line was written more like a curve connecting to the bottom line. In the ArabicGhubar writing, the bottom line was completely vertical, and the digit looked like a dotless closing question mark. Restoring the bottom line to its original horizontal position, but keeping the top line as a curve that connects to the bottom line leads to our modern digit.[11]
^Georges Ifrah,The Universal History of Numbers: From Prehistory to the Invention of the Computer transl. David Bellos et al. London: The Harvill Press (1998): 393, Fig. 24.62
