The silent T: castle, Christmas, often and fasten
Some English T's were pronounced for centuries and then dropped out of speech, while staying in the spelling. Most of them sit in the same place: after an S (or F), right before a weak syllable ending in L, N or M — castle, listen, fasten, often, Christmas.
Saying S-T-L or S-T-N with a fully weakened final syllable is awkward, and around the 17th century English speakers simplified the cluster by dropping the T. The spelling had already been settled, so the T stayed on the page.
Each word below has its full story on its own page.
castle
Castle comes from Latin castellum, and the T was once pronounced. English dropped it around the 1600s — the same change that silenced listen.
- Then · Old English / Old Northern French
- castel
- Say it
- KASS-ul
Christmas
Christmas is Christ's mass — Old English Cristes mæsse. Here is why the T went silent and why the "eye" of Christ became the short "i" of Christmas.
- Then · Old English
- Cristes mæsse
- Say it
- KRISS-muss
often
The T in often went silent in the 1600s, then came back. Here is why both OFF-en and OFF-ten are correct, and which one is more traditional.
- Then · Old English
- oft
- Say it
- OFF-en
fasten
Fasten is built from fast, as in "hold fast", and the T was once said. Here is how it went silent, and why fast and fasten no longer match.
- Then · Old English
- fæstnian
- Say it
- FASS-en
The one that came back
Often is the odd one out. Its T was dropped like the others, but because the letter is right there in the spelling, many speakers started pronouncing it again — a spelling pronunciation. Today both OFF-en and OFF-ten are accepted. Nobody has done the same for castle or fasten: "KAS-tul" and "FAS-ten" still sound wrong to native ears.
What this means for your accent
In this pattern — S or F, then T, then a weak -le, -en or -mas — leave the T out. Go straight from the S to the next consonant: KASS-ul, FASS-en, LISS-en, KRISS-muss. For often, either form is fine.
Questions people ask
+Why is the T silent in castle and listen?
Around the 17th century English dropped T between S and a final syllabic L or N. The spelling, already fixed, kept the letter.
+Should I pronounce the T in often?
Either is accepted. OFF-en is the traditional pronunciation; OFF-ten is a spelling pronunciation that many native speakers use.
More word stories
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The lost GH sound: night, daughter, laugh and though
English GH was once a real sound, like German Nacht. Here is how it went silent in night and daughter but turned into F in laugh.
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The silent L: walk, half, calm, could and salmon
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