(Henderson 2002) [4] The LIH is a subset of the lexicalist hypothesis, which states that morphology and syntax do not interact,[5] with the result (among others) that some syntactic operations cannot access word-internal structures.
[citation needed] The hypothesis seems to come about from the consensus that there is a phenomenon that generally and cross-linguistically prevents or limits the interaction between syntax and morphology.
Questions to be entertained, for example, are what constitutes a word and the point in which lexical insertion merges with sentence-level operations.
In this book, linguists Anna Maria Di Sciullo and Edwin S. Williams explore the concept of word atomicity, as well as the framing of syntax within the idea of a "sentence form" wherein sentences are skeletal placeholders of lexical items, such as listemes,[13] which are lexical constituents that are stored in the lexicon as opposed to generated by rules.
Lieber and Scalise argue that Chomsky's version of strict minimalism necessitates lexical items to be fully formed before entering syntactic operations.
[19] In English, the righthand head rule (RHHR) provides evidence for the division between the syntax and the lexical item.
[20] Bresnan & Mchombo (1995) identify five tests of lexical integrity which will be outlined below: extraction, conjoinability, gapping, inbound anaphoric islands and phrasal recursivity.
The LIH heavily depends on what constitutes a word or phrase, and violations to lexical integrity may occur in any given language with how they are defined.
For example, Haspelmath & Sims (2010) examines Hungarian with regards to words like meg-old [PFV-SOLVE] that are used in deverbal noun, and adjective formation.
'Haspelmath and Sims argue that the LIH is not violated in the data above if they think of megoldotta as a periphrastic construction, in which meg and oldotta are in separate syntactic nodes.
[27] Assuming that a "word" here is not a "morphologically generated form", but instead "terminal syntactic nodes"—a notion adopted by Ackerman & Lesourd (1997)—lexical integrity will not be violated.
This proposal runs counter to Hohenhaus (1998), who argues that there are some phrasal compounds that are non-lexicalizable, such as nonce words that are spontaneously coined once and in limited contexts, such as conversations.
The crucial evidence here is provided by "phrasal" parts which clearly stem from a different language or even a completely different sign system, such as: the @-sign, his rien-ne-va-plus-attitude.
[30] Spencer (2005) identifies another apparent violation to the LIH in the following examples: pre- and even to some extent post-war economics, pro- as opposed to anti-war, and hypo- and not hyperglycemic.
Complex predicates in this language may have non-verbal morphemes intervening within the constituents, for example: arrernelheme is split by the word akewele ('supposedly').