Allophone
In linguistics, an allophone is a variant of a phoneme that occurs in specific phonetic contexts. Allophones do not change the meaning of a word, but they can vary in pronunciation depending on their position in a word or the surrounding sounds. For example, the English phoneme /t/ has different allophones, such as the aspirated [t?] in "top" and the unaspirated [t] in "stop." Understanding allophones is important in language learning as it helps learners to produce accurate and natural-sounding speech.