Sloppy identity

In linguistics, sloppy identity is an interpretive issue involved in contexts like verb phrase ellipsis where the identity of the pronoun in an elided VP (verb phrase) is not identical to the antecedent VP.

For example, English allows VPs to be elided, as in example 1). The elided VP can be interpreted in at least two ways, namely as in (1a) or (1b) for this example.

In (1a), the pronoun his refers to John in both the first and the second clause. This is done by assigning the same index to John and to both the “his” pronouns. This is called the “strict identity” reading because the elided VP is interpreted as being identical to the antecedent VP.

In (1b), the pronoun his refers to John in the first clause, but the pronoun his in the second clause refers to Bob. This is done by assigning a different index to the pronoun his in the two clauses. In the first clause, pronoun his is co-indexed with John, in the second clause, pronoun his is co-indexed with Bob. This is called the “sloppy identity” reading because the elided VP is not interpreted as identical to the antecedent VP.

This sentence can have a strict reading:

Or a sloppy reading:

The discussion of “sloppy identity” amongst linguists dates back to a paper by John Robert Ross in 1967, in which Ross identified the interpretational ambiguity in the elided Verb Phrase of the previously stated sentence 1) found in the intro. Ross tried, without success, to account for “sloppy” identity using strictly syntactic structural relations, and concluded that his theories predicted too many ambiguities.

A linguist named Lawrence Bouton (1970) was the first to develop a syntactic explanation of VP-Deletion, commonly referred to by contemporary linguists as VP – ellipsis. Bouton's theory of VP-Deletion and Ross’ observation of sloppy identity served as an important foundation for linguists to build on.

Many advances followed within the next decade, providing much of the theoretical scaffolding necessary for linguists to address issues of “sloppy identity” up to present day. Most notable of these advances are Lawrence Bouton’s VP-Deletion rule (1970),Barbara Partee’s “Derived-VP rule” (1975), and Ivan Sag’s “Deletion Approach” (1976), based on the Derived-VP rule. It should be noted that theories beyond Ross’s initial discovery have all extended beyond analyses based on observations of structural relations, often using Logical Form and phonetic form to account of instances of sloppy and strict identity. The deletion (derived VP) approach, in combination with the use of Logical Form (LF) and phonetic form (PF) components to syntax, is one of the most widely used syntactic analysis of sloppy identity to date.

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