Editing Morpheme (section)

==Changing definitions==
{{Unreferenced section|date=September 2011}}
In [[generative grammar]], the definition of a morpheme depends heavily on whether syntactic trees have morphemes as leaves or features as leaves.
* Direct surface-to-[[syntax]] mapping in [[lexical functional grammar]] (LFG) – leaves are words
* Direct syntax-to-semantics mapping
** Leaves in syntactic trees spell out morphemes: [[distributed morphology]] – leaves are morphemes
** Branches in syntactic trees spell out morphemes: radical minimalism and [[nanosyntax]] – leaves are "nano-" (small) morpho-syntactic features

Given the definition of a morpheme as "the smallest meaningful unit", nanosyntax aims to account for idioms in which an entire syntactic tree often contributes "the smallest meaningful unit". An example [[idiom]] is "Don't let the cat out of the bag". There, the idiom is composed of "let the cat out of the bag". That might be considered a semantic morpheme, which is itself composed of many syntactic morphemes. Other cases of the "smallest meaningful unit" being longer than a word include some collocations such as "in view of" and "business intelligence" in which the words, when together, have a specific meaning.

The definition of morphemes also plays a significant role in the interfaces of generative grammar in the following theoretical constructs:
* [[Event semantics]]: the idea that each productive morpheme must have a compositional semantic meaning (a [[denotation]]), and if the meaning is there, there must be a morpheme (whether [[null morpheme|null]] or overt).
* [[Spell-out]]: the interface with which syntactic/semantic structures are "spelled out" by using words or morphemes with phonological content. That can also be thought of as lexical insertion into the syntactic.