Second, since -er also coincides with the comparative form of the adjective (11a), we might expect haplology in adjectives in which the stem ends in the syllable -er, by way of rule (10).
The comparative of helder 'clear' in (11b) is not helder with haplology of -er, but helderder (with a predictable insertion of [d], see Smith 1976).
(19) Proposed VI-rules for FEM: (second version) FEM [right arrow] in /X -- ,X[member of]([square root of]BAAS, [square root of]BOER, [square root of]HERDER, [square root of]HERTOG, [square root of]VRIEND, ...} Y--,Y = [-human] FEM [right arrow] ster / (*) -- FEM [right arrow] es 5 Haplology and special meanings
It is unclear why these cases are not realized with haplology of the -er affix before -ster: forms such as *zang-ster 'singer-FEM', *dicht-ster 'poet-FEM' and onderwijs-ster 'teacher-FEM' are all ill-formed.
By virtue of haplology, the passive morpheme is deleted on the surface.
In addition to the problems of analyzing bei as a preposition, the analysis of haplology in Chinese passives is also questionable.
Third, it is not clear in what situation haplology should apply.
Fourth, nonconcatenating homophonous elements cannot undergo haplology in Mandarin.
As pointed out by McCarthy and Prince (1995) and Yip (1998), MORPHDIS bans all kinds of haplology, in which two morphemes share overlapping contents.(12) In this paper, I propose that MORPHDIS is a constraint schema from which three universal constraints can be derived, [MORPHDIS.sub.LEX], [MORPHDIS.sub.[Alpha][Beta]], and [MORPHDIS.sub.MORPH].(13)
(38) forbids haplology to take place when the adjacent elements are both lexical.
The major difference between haplology of functional morphemes and haplology of lexical morphemes is that less information is lost in the former case by virtue of the nature of functional morphemes: functional morphemes constitute closed classes and mark grammatical or relational features.
A prediction is that no languages that allow haplology of lexical morphemes disallow haplology of functional morphemes.