On the status of intervening think-clauses in English long-distance dependency constructions

In each of these examples there is a dependency relation between the missing element, marked __, and the italicised word or words earlier in the sentence it is co-indexed with. In each example, the gap and its antecedent are separated by an intervening clause, hence the term ‘long-distance’ dependency. An alternative term is ‘unbounded’ dependency, which reflects the fact that the distance between the gap and its antecedent can in principle be made infinitely long by adding multiple intervening clauses, e.g. What do you think he told his wife his boss suspects he will try to do? The first two sentences in (1) are examples of a wh-dependency construction; (1a) is a wh-question, also called an open interrogative, while (1b) is a wh-relative. The third sentence is an example of a preposing construction. Standard generative grammar assumes that the antecedent in all three constructions originates in the position represented by the gap. In (1a), for example, the question word what is said to have been “extracted” out of that position, as a result of which it has come to occupy the leftmost position in what is analysed as a higher-ordered clause. In the minimalist program, where moves are kept as short as possible, long-distance dependencies arise through