In some cases an orthography based on the principle that symbols correspond to phonemes may lack characters to represent all the phonemes or all the phonemic distinctions in the language. This is called a defective orthography. An example in English is that the digraph th is required to represent two different phonemes (as in either and ether). A more systematic example is that of abjads like the Arabic and Hebrew alphabets, in which the short vowels are normally left unwritten and have to be inferred by the reader.
When an alphabet is borrowed to represent a different language than that for which it originally developed (as has been done with the Latin alphabet for many languages in Europe and elsewhere or Japanese Katakana being used for foreign words), it often proves to be defective in representing the new language's phonemes. Sometimes this problem is addressed by the use of such devices as digraphs (such as sh and ch in English, where pairs of letters represent single sounds), diacritics (like the caron on the letters š and č, which represent those same sounds in Czech), or the addition of completely new symbols (as some languages have introduced the letter w to the Latin alphabet).
Famous quotes containing the word defective:
“Now, since our condition accommodates things to itself, and transforms them according to itself, we no longer know things in their reality; for nothing comes to us that is not altered and falsified by our Senses. When the compass, the square, and the rule are untrue, all the calculations drawn from them, all the buildings erected by their measure, are of necessity also defective and out of plumb. The uncertainty of our senses renders uncertain everything that they produce.”
—Michel de Montaigne (15331592)