I

I is the ninth letter in the Latin alphabet, derived from the Greek iota (Ι, ι). It stood for the vowel /i/, the same as in the Etruscan alphabet. In Latin (as in Modern Greek) /j/ (as English Y in YOKE) was added. In Semitic, /j/ was the usual sound value of Jôd (probably originally a pictogram for an arm with hand), /i/ only in foreign words. In English, I represents different sounds, among them a diphthong that developed from /i:/ as well as short, open /I/ as in BILL.

A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z

In context, I is also:

• A word: the pronoun that is used in the English language by a person to refer to himself or herself.
• In chemistry, a symbol for the chemical element Iodine.
• In mathematics, the letter i is used for the imaginary unit, a complex number whose square is -1.
• In physics, often used symbol for current. The imaginary unit is represented by j instead.
• A symbol (I) for the closed unit interval, that is all real numbers from 0 to 1 inclusive, and also for the identity matrix.
• The Roman numeral for one.
• A Swedish film made in 1966, see I[?].