In linguistic morphology, fossilization refers to two close notions. One is preserving of ancient linguistic features which have lost their grammatical functions in language. Another is loss of productivity of a grammatical paradigm (e.g. of an affix), which still remains in use in some words.[1]
Examples of fossilization include fossilized morphemes and fossil words.
The term interlanguage fossilization refers to common types of errors made by most adult second-language learners, differing from the idiomatic usage of native-language learners.[2] These are erroneous generalizations or simplified language rules, which may be classified as phonological fossilization, lexical fossilization, syntactic fossilization and pragmatic fossilization.[3] These errors occur regardless of exposure to the language or education level.[4]