The object is not quite as compulsory as the subject: 'eat' is never without a subject, except in the imperative, but it may appears without an object. Yet, once given a ‘transitive’ verb is chosen by the speaker, the only information furnished by the the object as such results from the fact that it might have been suppressed. But in context where an object is actually found in 99 per cent of cases, its information is close to nil if considered in its object-function, and not as a specific choice among a variety of lexical or pronominal items. It is, therefore, normal that the most frequent type of object should not be marked by any specific segment, provided it is kept dinstinct from the subject by means of word order.
- Martinet (1962), a pag.150