1029: Null Pronominal Objects Oct 3, 2017

It is nearly impossible to consider something a grammatical rule, for a single language or multiple, even if one were to speak incredibly generally. For instance, to indicate agreement with personal pronouns and antecedents, English relies on word order, and in some cases—though by no means always—gender, number, and case. It is for this reason that in the sentences taken from Nature, Nurture and Universal Grammar, it is clear to a native speaker of English that in “John said that he thinks he should wash himself” the 'himself' refers to John, whereas in “John said that he thinks Bill should wash himself”, the 'himself' refers to Bill. In English, the pronoun is necessary, though in other languages that role can be filled when the pronoun would be indicated by the verb. In those languages where the pronoun can be omitted, the absent pronoun is called the 'variable pronominal' or 'null pronominal', depending upon how easily it can be omitted given context. It was thought, due to only logical assumption, that a transitive verb would require an obligatory pronominal object (like 'him') or it would agree in person and number with the optional, variable objects. Nevertheless, in Imbarbura Quechua, a pronoun can be null while there is no indication from the verb as to the presence of a variable object. For example, these lines taken from Null Objects in Universal Grammar show the Quechua (line 1), the verbatim translation (line 2), and then the English as a native-speaker would use it (line 3).
Juan munan Juzi Ø rijsichun
Juan wants Jose   know
Juan wants Jose to know him.
Any rule pertaining to grammar in general can be debunked, so to speak, with even one example, and since languages vary so greatly, there is perhaps nothing that can be said to be always true of grammar, past and present.