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 certain features of the subject argument or the sentence in which the subject figures. This phenomenon is known as Differential Subject Marking (DSM). Languages differ in which conditions govern DSM. Some languages differentiate their subjects on the basis of semantic features of the argument such as thematic role, volitionality, animacy, whereas others differentiate on the basis of clausal features such as...