One of the most fundamental, yet often neglected, or even paradoxical questions in the fieldof language acquisition is how children who have not yet acquired stable grammar can processlanguage and still manage to acquire new grammar. This question is further complicated bycross-linguistic differences, such as how English- and Japanese-speaking children process complexsentences in their respective languages. To answer these two intricate questions, we need toidentify cross-linguistically common – possibly universal or quasi-universal –characteristics in terms of the development of language processing strategies. At the same time,we also need to know whether different language processing strategies are used by children whospeak different languages. We thus need to take both developmental and cross-linguistic issuesinto consideration simultaneously.