Standard instances of N-ellipsis in English are introduced by a limited set of determiner- and adjective-like elements (possessives, cardinal and ordinal numbers, other quantifiers).
This observation is important for the theory N-ellipsis in general, and the discussion returns to the point below.
At times, the elided material can appear medially in the noun phrase, as just illustrated here with the b- and c-examples.
A related point is that N-ellipsis must be introduced by a pre-noun element in the noun phrase.
These data are (also) important because they bear on the formal account of N-ellipsis, a point that is considered in the next section.
There are three basic possibilities that one might pursue in order to develop a formal account of N-ellipsis: Each of these three analyses is illustrated here using tree structures of an example NP.
Each of these three analyses has its strengths and weaknesses, and which analysis is preferred varies based in part on the theoretical framework adopted.
Both analyses are challenged by the fact that they cannot explain why N-ellipsis is limited in occurrence in English to a relatively small number of pre-nominal elements.
The overt pronoun analysis can also account for the relatively small number of pre-nominal elements that can "introduce" ellipsis, since it reduces this ability down to a simple lexical characteristic of the pre-nominal elements involved.