Pro-drop language
A pro-drop language is a language in which certain classes of pronouns may be omitted when they can be pragmatically or grammatically inferable. The precise conditions vary from language to language, and can be quite intricate. The phenomenon of "pronoun-dropping" is part of the larger topic of zero or null anaphora. The connection between pro-drop languages and null anaphora relates to the fact that a dropped pronoun has referential properties, and so is crucially not a null dummy pronoun.
Pro-drop is a problem when translating to a non-pro-drop language such as English, which requires the pronoun to be added, especially noticeable in machine translation. It can also contribute to transfer errors in language learning.
An areal feature of some European languages is that pronoun dropping is not, or seldom, possible ; this is the case for English, French, German, and Emilian, among others. In contrast, Japanese, Mandarin Chinese, Vietnamese, Slavic languages, Finno-Ugric languages, Assyrian Neo-Aramaic, Kra-Dai languages, Italian, Spanish, and Portuguese exhibit frequent pro-drop features. Some languages, such as Greek and Hindi also exhibit pro-drop in any argument.
Usage of term
In Noam Chomsky's "Lectures on Government and Binding", the term is used for a cluster of properties of which "null subject" was one.Thus, a one-way correlation was suggested between inflectional agreement and empty pronouns on the one hand and between no agreement and overt pronouns, on the other. In the classical version, languages which not only lack agreement morphology but also allow extensive dropping of pronouns—such as Japanese, Chinese, Korean, and Vietnamese—are not included, as is made clear in a footnote: "The principle suggested is fairly general, but does not apply to such languages as Japanese in which pronouns can be missing much more freely.".
The term pro-drop is also used in other frameworks in generative grammar, such as in lexical functional grammar, but in a more general sense: "Pro-drop is a widespread linguistic phenomenon in which, under certain conditions, a structural NP may be unexpressed, giving rise to a pronominal interpretation.".
The empty category assumed to be present in the vacant subject position left by pro-dropping is known as pro, or as "little pro".
Cross-linguistic variation
It has been observed that pro-drop languages are those with either rich inflection for person and number or no such inflection at all, but languages that are intermediate are non-pro-drop.While the mechanism by which overt pronouns are more "useful" in English than in Japanese is obscure, and there are exceptions to this observation, it still seems to have considerable descriptive validity. As Huang puts it, "Pro-drop is licensed to occur either where a language has full agreement, or where a language has no agreement, but not where a language has impoverished partial agreement."
In pro-drop languages with a highly inflected verbal morphology, the expression of the subject pronoun is considered unnecessary because the verbal inflection indicates the person and number of the subject, thus the referent of the null subject can be inferred from the grammatical inflection on the verb.
Barbosa defines these typological patterns as null-subject languages, expressing that the term itself, pro-drop, can be subcategorized into categories such as: topic pro-drop, partial NSL and consistent NSL.
Topic pro-drop languages
In everyday speech there are instances when who or what is being referred to — namely, the topic of the sentence — can be inferred from context. Languages which permit the pronoun to be inferred from contextual information are called topic-drop languages: thus, topic pro-drop languages allow referential pronouns to be omitted, or be phonologically null. These dropped pronouns can be inferred from previous discourse, from the context of the conversation, or generally shared knowledge. Among major languages, some which might be called topic pro-drop languages are Japanese, Korean, and Mandarin. Topic prominent languages like Korean, Mandarin and Japanese have structures which focus more on topics and comments as opposed to English, a subject-prominent language. It is this topic-first nature that enables the inference of omitted pronouns from discourse.Korean
The following example from Jung Korean shows the omission of both pronouns in the subject and object position.Japanese
Consider the following examples from Japanese:The words in parentheses and boldface in the English translations appear nowhere in the Japanese sentences but are understood from context. If nouns or pronouns were supplied, the resulting sentences would be grammatically correct but sound unnatural. Learners of Japanese as a second language, especially those whose first language is non-pro-drop like English or French, often supply personal pronouns where they are pragmatically inferable, an example of language transfer.
Mandarin
The above-mentioned examples from Japanese are readily rendered into Mandarin:Unlike in Japanese, the inclusion of the dropped pronouns does not make the sentence sound unnatural.
Vietnamese
Vietnamese can naturally omit subjects, especially in universally casual clauses, proverbs and idioms:Partial pro-drop languages
Languages with partial pro-drop have both agreement and referential null subjects that are restricted with respect to their distribution. The partial null-subject languages include most Balto-Slavic languages, which allow for the deletion of the subject pronoun. Hungarian allows deletion of both the subject and object pronouns.Slavic languages
The following table provides examples of subject pro-drop in Slavic languages. In each of these examples, the 3rd person masculine singular pronoun 'he' in the second sentence is inferred from context.| Language | ' | ' is coming.' |
| Belarusian | Бачу . Baču . | Ідзе. Idze. |
| Bulgarian | Виждам го. Vizhdam go. | Идва. Idva. |
| Czech | Vidím ho. | Jde. |
| Macedonian | Го гледам. Go gledam. | Доаѓа. Doaǵa. |
| Polish | Widzę go. | Idzie. |
| Russian | Вижу . Vižu . | Идёт. Idët. |
| Serbo-Croatian | Vidim ga. Видим га. | Dolazi. Долази. |
| Slovene | Vidim ga. | Prihaja. |
| Ukrainian | Бачу . Bachu . | Іде. Ide. |
In the East Slavic languages, even the objective pronoun его can be omitted in the present and future tenses. In these languages, the missing pronoun is not inferred strictly from pragmatics, but partially indicated by the morphology of the verb. However, the past tense of both imperfective and perfective in the modern East Slavic languages inflects by gender and number but not person because the present tense conjugations of the copula "to be" have practically fallen out of use. As such, the pronoun is often included in these tenses, especially in writing.
Finno-Ugric languages
In Finnish, the verb inflection replaces first- and second-person pronouns in simple sentences: menen "I go", menette "all of you go". Pronouns are typically left in place only when they need to be inflected, e.g. me "we", meiltä "from us". There are possessive pronouns but possessive suffixes, e.g. -ni as in kissani "my cat", are also used, as in Kissani söi kalan. A peculiarity of Colloquial Finnish is that the pronoun me can be dropped if the verb is placed in the passive voice. Estonian, a close relative of Finnish, has a tendency that is less clear. Literary Estonian generally uses explicit personal pronouns in the literary language, but they are often omitted in colloquial Estonian.Hungarian is also pro-drop, and subject pronouns are used only for emphasis: mentem "I went". Because of the definite conjugation, object pronouns can be often elided as well. For example, the question látjátok a macskát? "Do see the cat?" can be answered with just látjuk " see " because the definite conjugation renders the object pronoun superfluous.
Hebrew
Modern Hebrew, like Biblical Hebrew, is a "moderately" pro-drop language. In general, subject pronouns must be included in the present tense. Since Hebrew has no verb forms expressing the present tense, the present tense is formed by using the present participle. The Hebrew participle, as is the case with other adjectives, declines only in grammatical gender and number, thus:Since the forms that are used for the present tense lack the distinction between grammatical persons, explicit pronouns must be added in most cases.
In contrast, the past tense and the future tense the verb form is inflected for person, number, and gender. Therefore, the verb form itself indicates sufficient information about the subject. The subject pronoun is therefore normally dropped, except in third-person.
Many nouns can take suffixes to reflect the possessor in which case the personal pronoun is dropped. In daily usage, the inflection of Modern Hebrew nouns is common only for some nouns. In most cases, inflected possessive pronouns are used. In Hebrew, possessive pronouns are treated mostly like adjectives and follow the nouns which they modify. In Biblical Hebrew, inflection of more sophisticated nouns is more common than in modern usage.