The spelling of the word "forty" may seem unusual, but it's actually quite consistent with English phonetics. The combination of the letters "f-o-r-t-y" is pronounced as /ˈfɔːrti/ in the International Phonetic Alphabet (IPA). The reason for the spelling is because English used to have a system of number words that ended in "-ty" instead of "-teen" (e.g. thirty, fifty). This system has mostly disappeared, but "forty" is one of the few remnants. So while it may look strange, "forty" is just following the rules of English spelling and pronunciation.
Forty is an adjective and number that typically represents the quantity or value of four times ten, equivalent to the Arabic numeral 40. It falls between the numbers thirty-nine and forty-one in the numerical sequence. The word "forty" is derived from the Old English word "feowertig," which literally means "four tens." It is commonly used in both written and spoken language to denote a specific quantity, age, or period.
As a quantity, "forty" often represents a sizable amount, implying a significant number or a large extent of something. It is used to describe a grouping of objects totaling forty, or to indicate a numeral that corresponds with the value of forty. In terms of age, "forty" refers to an individual who has reached the milestone of forty years since birth. It is frequently associated with middle age and is considered a significant transition period in a person's life.
Further, "forty" can also be employed to denote a duration or a specific period. It can refer to a span of time that encompasses forty units, whether those units are minutes, hours, days, weeks, months, or years. This usage is often encountered in expressions like "forty days and forty nights," which is a biblical allusion to a period of prolonged duration or testing.
In summary, "forty" is an adjective and number that signifies the value of four times ten and is used to describe quantity, age, or duration.
Four times ten.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.
* The statistics data for these misspellings percentages are collected from over 15,411,110 spell check sessions on www.spellchecker.net from Jan 2010 - Jun 2012.
The word "forty" comes from Old English "feowertig", which is a combination of "feower" meaning "four" and "tig" meaning "group of ten". It is related to other Germanic languages such as Dutch "veertig" and German "vierzig", all deriving from the same Proto-Germanic root.