Metathesis is when two sounds swap positions inside a word — the spelling stays the same, but the order in which you actually pronounce the sounds changes.
The clearest American English example is "comfortable":
| Letters | c | o | m | f | or | t | a | b | l | e |
|---|---|---|---|---|---|---|---|---|---|---|
| Careful sounds | k | ʌ | m | f | ər | t | ə | b | ə | l |
| Natural sounds | k | ʌ | m | f | t | ər | — | b | ə | l |
The r sound from the or letters physically comes out of your mouth AFTER the t — even though the letters are spelled in the opposite order. The unstressed a schwa then drops entirely (schwa deletion).
Metathesis is lexicalized — it doesn't apply by general rule, only to specific words. In American English, the most common pattern is "or + t" reordering to "t + ər" in:
| Word | Careful | Natural |
|---|---|---|
| comfortable | /ˈkʌmfərtəbəl/ | /ˈkʌmftərbəl/ |
| comfortably | /ˈkʌmfərtəbli/ | /ˈkʌmftərbli/ |
| uncomfortable | /ʌnˈkʌmfərtəbəl/ | /ʌnˈkʌmftərbəl/ |
| uncomfortably | /ʌnˈkʌmfərtəbli/ | /ʌnˈkʌmftərbli/ |
(Words derived from "comfortable" with an unstressed or immediately before a t. Other comfort-family words like "comforter" and "comforting" do NOT consistently metathesize in natural speech — they keep the careful "or + t" order.)
Linguistically, metathesis often makes a word easier to say. The "or-t" → "t-ər" reordering avoids an awkward sequence of unstressed schwa-r followed by a t followed by another unstressed schwa. Moving the r-sound after the t produces a cleaner consonant cluster (ft) and a single r-colored vowel for the next syllable.
This is the same process that historically turned:
In all three, an r switched places with the vowel next to it. Modern "comfortable" is an example of metathesis still happening live in pronunciation today — even though the spelling stays the historical/Latin form.
When you grade your pronunciation of comfortable, you'll see:
or letters appear with a "→" arrow superscript (sound moved away)t cell shows tər instead of just t (sound arrived here)This signals that the standard letter-to-sound mapping doesn't work for this word. The "or" letters are part of the word's spelling, but their sound is heard later in the word.