An allophone is a spoken sound of language, a variation within a "phoneme." Therefore, to understand "allophone" you should first understand "phoneme." A "phoneme" is a speech sound that can change the meaning of a word. For example, in English, /t/ and /d/ are phonemes because if you change "ten" to "den," the meaning of the word changes. Allophones are variations within a phoneme: they are speech sounds that are not exactly alike but that do not (cannot) change the meaning of a word in a specific language. For example, in English you can make a /t/ or /d/ sound by putting the tip of your tongue on the top of your mouth or by putting it on your teeth. Either way, the meaning of a word will not change. Speech sounds that are phonemes in one language may be only allophonic variations in another language. For exampe, in English, /l/ and /r/ are phonemes (because "lie" and "rye" have different meanings). But in some languages, interchanging /l/ and /r/ might make the pronunciation sound strange, but it can never change the meaning of a word: the sounds are merely allophones (variations) of the same phoneme. NOTE: Most phoneticians agree that phonemes and allophones are "convenient fictions"; concepts that were invented to explain certain features of language.