Languages differ in the types of overt movement they display. For example, some languages (including English) require subjects to move to a preverbal position, while others (including Italian) allow subjects to remain postverbal. In its current form, Minimalism offers no real answer to the question of why these different types of movements are distributed among languages as they are.
In Uttering Trees, Norvin Richards investigates the conditions imposed upon syntax by the need to create syntactic objects that can be interpreted by phonolog—that is, objects that can be pronounced. Drawing extensively on linguistic data from a variety of languages, including Japanese, Basque, Tagalog, Spanish, Kinande (Bantu language spoken in the Democratic Republic of the Congo), and Chaha (Semitic language spoken in Ethiopia), Richards makes two new proposals about the relationship between syntax and phonology.