Pro-drop parameter
One of the important parameters in UG is pro-drop
parameter. A pro-drop language is a language in which certain classes of
pronouns may be omitted when they are in some sense pragmatically inferable.
The phenomenon of "pronoun-dropping" is also commonly referred to in
linguistics as zero or null anaphora.
In everyday speech there are often instances when
who or what is being referred to can be inferred from context. Proponents of
the term "pro-drop" take the view that pronouns which in other
languages would have those referents can be omitted, or be phonologically null.
Among major languages, what might be called a pro-drop language is Japanese
(featuring pronoun deletion not only for subjects, but for practically all
grammatical contexts). Chinese, Slavic languages, and American Sign Language
also exhibit frequent pro-drop features.
Some languages might be considered only partially
pro-drop in that they allow deletion of the subject pronoun. These null subject
languages include many Romance languages such as Spanish, Italian, Occitan,
Catalan, Portuguese, and Romanian (French is the most notable exception), as
well as all the Balto-Slavic languages.
