My question came from looking at this one Why is "math" always pluralized in British English and singular in American English?. Why are words like Mathematics and Physics pluralised? On a side note i just noticied that i used an 's' instead of a 'z' in pluralised. Why do some countries use 's' and others 'z' in some words?
marked as duplicate by kiamlaluno, RegDwigнt♦, Kosmonaut Feb 9 '11 at 15:02
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The OED generally prefers the 'z' over the 's' forms of words in modern English usage. The 's' forms often relate to archaic Norman roots of words; and today, the 's' forms are normally found in areas where both French and English still mix (for example, in Canadian English).