I is the ninth letter

Letter (alphabet)

A letter is a grapheme in an alphabetic system of writing, such as the Greek alphabet and its descendants. Letters compose phonemes and each phoneme represents a phone in the spoken form of the language....

 and a vowel

Vowel

In phonetics, a vowel is a sound in spoken language, such as English ah! or oh! , pronounced with an open vocal tract so that there is no build-up of air pressure at any point above the glottis. This contrasts with consonants, such as English sh! , where there is a constriction or closure at some...

 in the basic modern Latin alphabet

Basic modern Latin alphabet

The International Organization for Standardization basic Latin alphabet consists of the following 26 letters:By the 1960s it became apparent to the computer and telecommunications industries in the First World that a non-proprietary method of encoding characters was needed...

.


In Semitic

Semitic

In linguistics and ethnology, Semitic was first used to refer to a language family of largely Middle Eastern origin, now called the Semitic languages...

, the letter may have originated in a hieroglyph

Egyptian hieroglyphs

Egyptian hieroglyphs were a formal writing system used by the ancient Egyptians that combined logographic and alphabetic elements. Egyptians used cursive hieroglyphs for religious literature on papyrus and wood...

 for an arm that represented a voiced pharyngeal fricative

Voiced pharyngeal fricative

The voiced pharyngeal approximant or fricative is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents it is , and the equivalent X-SAMPA symbol is ?\....

 (/ʕ/) in Egyptian

Egyptian language

Egyptian is the oldest known indigenous language of Egypt and a branch of the Afroasiatic language family. Written records of the Egyptian language have been dated from about 3400 BC, making it one of the oldest recorded languages known. Egyptian was spoken until the late 17th century AD in the...

, but was reassigned to /j/ (as in English "yes") by Semites, because their word for "arm" began with that sound. This letter could also be used to represent /i/, the close front unrounded vowel

Close front unrounded vowel

The close front unrounded vowel, or high front unrounded vowel, is a type of vowel sound, used in many spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ....

, mainly in foreign words.

The Greeks adopted a form of this Phoenician

Phoenician alphabet

The Phoenician alphabet, called by convention the Proto-Canaanite alphabet for inscriptions older than around 1050 BC, was a non-pictographic consonantal alphabet, or abjad. It was used for the writing of Phoenician, a Northern Semitic language, used by the civilization of Phoenicia...

 yodh as their letter iota

Iota

Iota is the ninth letter of the Greek alphabet. In the system of Greek numerals it has a value of 10. It was derived from the Phoenician letter Yodh . Letters that arose from this letter include the Roman I and J and the Cyrillic І , Yi , Je , and iotified letters .Iota represents...

(⟨Ι, ι⟩) to represent /i/, the same as in the Old Italic alphabet

Old Italic alphabet

Old Italic refers to several now extinct alphabet systems used on the Italian Peninsula in ancient times for various Indo-European languages and non-Indo-European languages...

.