books.google.fr - Although (almost) all sentences have subjects, not all sentences encode their subjects in the same way. Some languages overtly mark some subjects, but not others, depending on semantic features of the subject argument or the sentence in which the subject figures. This phenomenon is known as Differential...http://books.google.fr/books/about/Differential_Subject_Marking.html?hl=fr&id=UQKCofxuhlMC&utm_source=gb-gplus-shareDifferential Subject Marking
