often

: 15th-century England saw a tendency among speakers of English to omit some consonants in an effort to pronounce some words more easily. Such was the case with the letter t in often. To this day, the preferred pronunciations of this word are /áwf'n, óff'n, /, though some speakers do pronounce the t. Other words, such as listen, soften, hasten, and glisten, in which the t is never pronounced, reflect that same 15th-century trend.