The meaning of I is the 9th letter of the English alphabet. How to use i in a sentence. me or I?: Usage Guide., From Latin i, minuscule of I. i (lower case, upper case I, plural is or i's) The ninth letter of the English alphabet, called i and written in the Latin script. The English letter i represents many different sounds, often the diphthong /aɪ/ (from Middle English /iː/), as in the pronoun I, or /ɪ/ as in b i t. i (lower case, upper case I), In modern English the sound of short i is almost identical to what it was in Latin—e.g., in the word pit. Long i has become a diphthong (ai, as in the word ice), its former sound as a high front vowel having been assumed by long e as its position shifted forward and upward., I, i definition: 1. the ninth letter of the English alphabet 2. the sign used in the Roman system for the number 1…. Learn more., I's, Is, i's, is. the ninth letter of the English alphabet, a vowel. any spoken sound represented by the letter I or i, as in big, nice, or ski. a written or printed representation of the letter I or i. a device, as a printer's type, for reproducing the letter I or i. us ., I meaning, definition, what is I: used by the person speaking or writing t: Learn more..