The Initial Teaching Alphabet (or I.T.A. or i.t.a.) was developed by Sir James Pitman (the grandson of Sir Isaac Pitman, inventor of a system of shorthand) in the early 1960s. It was not intended to be a strictly phonetic transcription of English sounds, or a spelling reform for English as such, but instead a practical simplified writing system which could be used to teach English-speaking children to read more easily than can be done with traditional orthography. After children had learned to read using I.T.A., they would then eventually transition to standard English spelling. Although it achieved a certain degree of popularity in the 1960s, it has fallen into disuse.
The I.T.A. originally had 43 symbols, which was expanded to 44, then to 45. Each symbol predominantly represented a single English sound (including affricates and diphthongs), but there were complications due to the desire to avoid making I.T.A. needlessly different from standard English spelling (which would make the transition from I.T.A. to standard spelling more difficult), and in order to neutrally represent several English pronunciations or dialects. In particular, there was no separate I.T.A. symbol for the English schwa sound [ə], and schwa was written with the same letters used to write full vowel sounds. There were also several different ways of writing unstressed [ɪ]/[i] and consonants palatalized to [tʃ], [dʒ], [ʃ], [ʒ] by suffixes. Consonants written by double letters or "ck", "tch" etc. sequences in standard spelling were written with multiple symbols in I.T.A.
The I.T.A. symbol set includes joined letters (typographical ligatures) to replace the two-letter digraphs "wh", "sh", and "ch" of conventional writing, and also ligatures for most of the long vowels. There are two distinct ligatures for the voiced and unvoiced "th" sounds in English, and a special merged letter for "ng". There is a variant of the "r" to end syllables, which is essentially silent in Received Pronunciation but with a special sound in General American, Scots English and some other British regional accents (this was the 44th symbol added to the I.T.A.).
Each of the symbols has a name, the pronunciation of which includes the sound that the character stands for. For example, there is a backwards "z" to replace the "s" of standard spelling where it is voiced. The name of this letter is "zess".
There are two English sounds which each have more than one I.T.A. letter whose main function is to write them. So whether the sound [k] is written with the letters "c" or "k" in I.T.A. depends on the way the sound is written in standard English spelling, as also whether the sound [z] is written with the ordinary "z" letter or with the backwards "z" letter zess (which resembles an angular form of the letter "s").
A special typeface was created for the I.T.A., whose characters were all lower case. Where capital letters are used in standard spelling, the I.T.A. simply used larger versions of the same lower-case characters. The following chart shows the symbols of the 44-character version of the I.T.A., with, underneath each one, its pronunciation represented by a symbol of the International Phonetic Alphabet:
Note that "d" is made more distinctively different from "b" than is usual in standard typefaces (which is possible since in I.T.A. there is no "q").
Later a 45th symbol was added to accommodate local ways of pronouncing English, a form of diaphonemic writing. In the original set, a "hook a" or "two-storey a" was used for the sound in "cat", and a "round a" or "one-storey a" for the sound in "father". But Americans and Canadians generally do not pronounce the words "rather", "dance", and "half" with this latter sound, so a new character, the "half-hook a", was devised that could be taken either way by the appropriate speech dialect community (to avoid the necessity of producing separate instructional materials for speakers of different varieties of English).
Any advantage of the I.T.A. in making it easier for children to learn to read English was often offset by some children not being able to effectively transfer their I.T.A.-reading skills to reading standard English orthography, and/or being generally confused by having to deal with two alphabets in their early years of reading. Certain alternative methods (such as associating sounds with colours, so that for example when the letter "c" writes a [k] sound it would be coloured with the same colour as the letter "k", but when "c" writes an [s] sound it could be coloured like "s") were found to have some of the advantages of the I.T.A. without most of the disadvantages. Though the I.T.A. was not originally intended to dictate one particular approach to teaching reading, it was often identified with phonics methods, and after the 1960s, the pendulum of educational theory swung away from phonics.
The I.T.A. remains of interest in discussions about possible reforms of English spelling. There have been attempts to apply the I.T.A. using only characters which can be found on the typewriter keyboard or in the basic ASCII character set, to avoid the use of special symbols.