An accidental gap is a non-existing word which is expected to exist given the hypothesized morphological rules of a particular language.
In English it is possible to derive nouns from verbs by adding the suffixes -al and -(a)tion to the verbal stem. However, some such derivations do not exist, although there are no grammatical reasons for their nonexistence. Compare the following examples:
recite recital recitation propose proposal proposition
arrive arrival *arrivation refuse refusal *refusation
derive *derival derivation describe *describal description
In the literature, an accidental gap is usually thought of as a hole in a paradigm.
- Allen, M.R. 1978. Morphological Investigations, PhD diss. Univ. of Connecticut.
- Bochner, H. 1988. The forms of Words: a Theory of Lexical Relationships, PhD diss. Harvard Univ. Cambridge.
- Halle, M. 1973. Prolegomena to a Theory of Word-Formation. Linguistic Inquiry 4, 451-464.
- Scalise, S. 1984. Generative Morphology. Foris, Dordrecht.
- Spencer, A. 1991. Morphological Theory. Blackwell, Oxford.