Last November a visitor to the Grammar Shop of the Alpha Agora asked about the construction, “I thought her not so pretty” and I only got around to replying today. Here are my thoughts. They point up an interesting difference between languages with case systems (nouns with endings which change with changes in sentence functions) and without them. English is in the final stage of losing its cases.
There are several verbs that accept direct objects with ‘predicate’ adjectives, most have to do with mental processing. It is parallel to consider, as in “I consider that she is pretty” or, shortened, “I consider her pretty,” “I imagined her pretty;” “I imagined that she would be pretty” or “I imagined her pretty.”
It is a peculiar prerogative of English which allows predicates of nouns in the objective case. In languages like German and Russian, where the objectives (accusative) case is used only for direct objects and direct objects cannot be the subject of a phrase, such constructions are impossible. Notice that in the shortened sentences above her is the direct object of the main sentence and subject of the dependent clause “her (=she is) pretty”.
We do this elsewhere, too, usually using the infinitive construction. In the sentence “I asked her to do it,” her is the direct object of asked and the subject of do it at the same time. In languages with real case systems, this is impossible. It is possible in English because the case system has vanished except for the pronouns I, we, he, she and our comfort level with constructions like between you and I show that it is on the way out even for these pronouns.