pro-drop (adj.)

A term used in GOVERNMENT-BINDING THEORY for a PARAMETER which determines whether the SUBJECT of a CLAUSE can be suppressed. Italian is a pro-drop language, in this sense, because it can have subjectless sentences (e.g. E pericoloso ‘It is dangerous’); by contrast, English is a non-pro-drop language, as the translation of the Italian sentence indicates. Other properties of pro-drop languages have been suggested, such as that they have a rich system of VERB-AGREEMENT, and free INVERSION of subject and verb. Pro-drop languages are also known as ‘NULL subject’ languages. Languages that can drop not only subjects but also objects and other phrases are called radical pro-drop (e.g. Japanese).