What is Fossilization?
Fossilization is when an error becomes a permanent habit in a learner's speech — a wrong ending, a misplaced sound, a grammar shortcut — repeated so often, uncorrected, that it hardens into the learner's version of the language, resisting later fixing.
It typically happens to learners who communicate successfully despite the error: since everyone understands them anyway, nothing pushes the correction, and thousands of repetitions cement the mistake. Long-term immigrants who plateaued decades ago are the textbook example.
The antidote is timely feedback: hearing the correct form soon after producing the wrong one, repeatedly, before the habit sets. This is why input-only learning can quietly fossilise pronunciation — you can't hear your own accent drifting.
What it means for your speaking
Speaking a lot without feedback risks fossilising errors; not speaking at all risks something worse — fossilised silence. The sweet spot is conversation with gentle, immediate correction, which is exactly the job of a coach that flags what you actually struggled to say.
Practise out loud — 30 seconds a day →