In linguistics, a compound verb or complex predicate is a multi-word compound that acts as a single verb. One component of the compound is a light verb or vector, which carries any inflections, indicating tense, mood, or aspect, but provides only fine shades of meaning. The other, "primary", component is a verb or noun which carries most of the semantics of the compound, and determines its arguments. It is usually in either base or conjunctive participial form. There simple sentences and Compound Sentences. A compound verb is also called a "complex predicate" because the semantics, as formally modeled by a predicate, is determined by the primary verb, though both verbs appear in the surface form. Whether Noun+Verb (N+V) compounds are considered to be "compound verbs" is a matter of naming convention. Generally, the term complex predicate usually includes N+V compounds, whereas the term compound verb is usually reserved for V+V compounds. However, several authors also refer to N+V compounds as compound verbs. Compound verbs are to be distinguished from serial verbs which typically signify a sequence of actions, and in which the verbs are relatively equal in semantic and grammatical weight, and from auxiliary verbs.

Thus, there are two classes of complex predicates: V+V compounds: The true compound verb, where the first verb (or the second...) is a Light verb (LV), followed by (or preceded by...) a primary or Heavy verb. With a few exceptions all compound verbs alternate with their simple counterparts. That is, removing the light verb / vector does not affect grammaticality at all nor the meaning very much: ????? nikala '(He) went out.' In a few languages both components of the compound verb can be finite forms: Kurukh kecc-ar ker-ar lit. "died-3pl went-3pl" '(They) died.' N+V compounds: A compound with Noun+verb, converting the noun into a verbal structure; the arguments and the semantics are determined by the N and the tense markers / inflections are carried by the V. This would include English stretched verb examples like take a walk or commit suicide. Often the Verbs participating N+V compounding are also those that participate as LVs in V+V compounds. The N+V compound appears in almost all languages, especially with LVs such as "do," "make," etc., and are sometimes not considered to be a true compound verb. Compound verbs are very common in all the languages of India, though they are more frequent in the northern Indo-Aryan languages than in Dravidian languages. In addition to Hindi-Urdu and Panjabi, they occur in other Indo-Iranian languages like Persian, Marathi and Nepali, in Tibeto-Burman languages like Limbu and Newari. Also, they are very frequent in Altaic languages like Korean, Japanese, and in Turkic languages Tatar, Kazakh, Nogai, Uyghur, Uzbek, Bashkir and Kyrgyz, and in northeast Caucasian languages like Tsez and Avar. The Indo-European language Greek also possesses some verb–verb compounds. Conventionally, the English language expresses fine distinctions as to the beginning, duration, completion, or repetition, of an action in the form of compound verbs, using auxiliaries or other lexical mechanisms. Examples here include was starting, had lived, had been seen, etc.[1] This usage reduced the need to create complex predicates. Though V+V compound verbs are rare in English, one may illustrate the form with the example "start reading". In some interpretations, one may consider "start" as a light verb, which carries markers like tense. However, the main part of the meaning, as well as the arguments of "started reading", i.e. answers to questions such as who? (agent), or what was it that he "started reading" (object) are determined by the second, primary verb, "read". Note that "start" also modifies the meaning or the semantics, by focusing on the early part of the "reading". Also note that "start" carries plural/tense markers (they start|he starts reading), whereas "reading" appears in this fixed form, and does not change with tense, number, gender etc. Whether gerundive forms like "start reading" are compound verbs is controversial in English; many linguists prefer to treat "reading" as a nominal in its gerundive form. However, the compound verb treatment may have some advantages, particularly when it comes to semantic analysis. For example, in X starts reading Y, the question what did X start is less revealing than what did x "start reading". English has many examples of N+V compound predicates: see stretched verb. Sometimes examples from English cited for compound verbs turn out to be serial verbs, e.g.: What did you go and do that for?; or your business might just up and leave.