Head of Relative Clause and Relativized Position
In grammatical terms, the noun phrase modified by the relative clause is sometimes called “the head noun phrase” or “the head” of the relative clause. And the targeted position within the relative clause (the subject position or the gap) is called the “relativized position.” Using these terms will facilitate the discussion of research associated with the acquisition of English relative clauses.
Research on the acquisition of English relative clauses has often focused on the relationship between the head noun phrase of the relative clause and the relativized position within the relative clause. For example, is the head noun phrase the subject or the object within the main clause, and is the relativized position the subject or the object within the relative clause. If we focus only on these positions, there are four kinds of sentences containing relative clauses:
Four Sentence Types
The sentences below illustrate the four sentence types:
In the SS sentence, for example, the employer is the subject of the main clause, and who represents the subject of the relative clause. In the OO sentence the lawyer is the object of visited within the main clause, and the gap within the relative clause represents the object of hired.
Deaf Students’ Knowledge of Four Sentence Types
With respect deaf students’ knowledge of such relative clause sentences, results are mixed.Quigley, Smith, and Wilbur (1974) found that deaf children and adolescents generally had greater knowledge of OS and OO relative clause sentences than of SS and SO sentences. In another study, de Villiers (1988) found that deaf children performed the best on SS sentences and not very well on the other types. The two studies used different methodologies and focused on deaf students with different characteristics, which might explain the contradictory results.
At the college level, Lillo-Martin, Hanson, and Smith (1992) got results that were similar to the results of Quigley, Smith, and Wilbur (1974). That is, deaf college students had better knowledge of OS and OO relatives. In a study of deaf college students’ production of English relative clauses, Berent (2000) found that the vast majority of relative clause sentences produced by the students were OS and OO relatives. From these studies, most of the evidence suggests the following:
Deaf students have greater knowledge of OS and OO relative clause sentences than SS and SO sentences.
“Right-Branching” and “Center-Embedded” Relative Clauses
The most likely reason for this greater knowledge of OS and OO sentences is that, in these sentence types, the relative clause “branches to the right of the main clause.” Therefore, the relative clause does not “interrupt” the SUBJECT-VERB OBJECT constituents of the main clause.
In contrast, in SS and SO sentences, the relative clause falls right in the center of the main clause and interrupts the main clause constituents. As noted in Berent (1988), an SO sentence will have the following sequence of major constituents, including wh-words but ignoring gaps:
However, an OS sentence will have the following sequence:
Apparently, the OS ordering is easier to process that the SO ordering, with its adjacent subjects and adjacent verbs.
With respect to SS sentences, Quigley and King (1980) noted that deaf students often misinterpret the subject of the action expressed by the relative clause. For example, in the SS sentence above (The employer who visited the lawyer hired the photographer.), some students might interpret the sentence to mean, in part, that the lawyer hired the photographer. This might happen because the lawyer is followed immediately by hired. Therefore, to some students the lawyer looks like the subject of hired.