In linguistics, a light verb is a verb that has little semantic content of its own and forms a predicate with some additional expression, which is usually a noun. Common verbs in English that can function as light verbs are do, give, have, make, take, etc. Other names for light verb include delexical verb vector verb, explicator verb, thin verb, empty verb or semantically weak verb (a semantically weak verb is not to be confused with a weak verb of the Germanic weak inflection, however). While light verbs are similar to auxiliary verbs regarding their meaning contribution to the clauses in which they appear, light verbs fail the diagnostics that identify auxiliary verbs and are therefore distinct from auxiliaries.
Light verb constructions challenge theories of compositionality because the words that form such constructions do not together qualify as constituents although the word combinations qualify as catenae.
Most light verb constructions in English include a noun and are sometimes called stretched verbs. Some light verb constructions also include a preposition, e.g.
- They did the review of my paper first.
- Sam did the cleaning yesterday.
- Who got such intense criticism?
- Susan is getting much support from her family.
- I am going to have a nice nap.
- She had a smoke.
- We had a slow, boring conversation.
- Are you giving a presentation at the conference?
- They gave the kids a hard time.
- Who will give you a hug?
- Who made such a severe mistake?
- I made the first request.
- Sam has taken a shower.
- Why is Larry taking a nap?
- We should take a break soon.
- Have you taken advantage of that opportunity.
- I haven't taken that into consideration.
The light verbs are underlined, and the words in bold together constitute the light verb constructions. Each of these constructions is the (primary part of the) main predicate of the sentence. Note that the determiner a is usually NOT part of the light verb construction. We know that it is not part of the light verb construction because it is variable, e.g. I took a long/the first/two/the best nap. The light verb contributes little content to its sentence; the main meaning resides with the noun in bold.
Alternative constructions with full verbs
Many light verb constructions are closely similar in meaning to a corresponding full verb, e.g.
- a. Sam did a revision of his paper. - Light verb construction
- b. Sam revised his paper. -Full verb
- a. Larry wants to have a smoke. - Light verb construction
- b. Larry wants to smoke. - Full verb
- a. Jim made an important claim that.... - Light verb construction
- b. Jim claimed that... - Full verb
- a. Mary is taking a nap. - Light verb construction
- b. Mary is napping. - Full verb
Alternative formulations such as these lead to the insight that light verb constructions are predicates just like the corresponding full verb alternatives. There can be, however, nuanced differences in meaning across these alternative formulations. The light verb constructions produce possibilities for modification that are less available with the corresponding full verb alternatives.
Light verbs vs. auxiliary verbs and full verbs
Many verbs that serve as light verbs can also serve as auxiliary verbs and/or full verbs depending on the context in which they appear. Light verbs are similar to auxiliary verbs insofar as they contribute mainly functional content (as opposed to semantic content) to the clauses in which they appear. Light verbs, however, are not auxiliary verbs, nor are they full verbs. Light verbs differ from auxiliary verbs in English insofar as they do not pass the syntactic tests that identify auxiliary verbs. The following examples illustrate that light verbs fail the inversion and negation diagnostics that identify auxiliary verbs:
- a. He did call Susan yesterday.
- b. Did he call Susan yesterday? - The auxiliary did inverts with the subject.
- c. He did not call Susan yesterday? - The auxiliary did can take not as a postdependent.
- a. He did the review of my paper yesterday.
- b. *Did he the review of my paper yesterday? - The light verb did cannot invert with the subject.
- c. *He did not the review of my paper yesterday. - The light verb did cannot take not as a postdependent.
- a. He has opened the window.
- b. Has he opened the window? - The auxiliary has inverts with the subject.
- c. He has not opened the window. - The auxiliary has takes not as a postdependent.
- a. She had a smoke.
- b. *Had she a smoke? - The light verb had cannot invert with the subject.
- c. *She had not a smoke. - The light verb had cannot take not as a postdependent.
Light verbs differ from full verbs in that light verbs lack the semantic content that full verbs have. Full verbs are the core of a predicate, whereas light verbs form a predicate with another expression (often a noun) with full semantic content. This distinction is more difficult to illustrate, but it can be seen in the following examples involving reflexive pronouns:
- a. Jim1 took a picture of himself1. - The light verb took requires the reflexive pronoun to appear.
- b. *Jim1 took a picture of him1. - The light verb took prohibits the simple pronoun from appearing.
- a. Jim1 took a picture of himself1 to school. - The full verb took allows the reflexive pronoun to appear.
- b. Jim1 took a picture of him1 to school. - The full verb took allows the simple pronoun to appear.
- a. Sally1 gave a description of herself1. - The light verb gave requires the reflexive pronoun to appear.
- b. *Sally1 gave a description of her1. - The light verb gave prohibits the simple pronoun from appearing.
- a. Sally1 gave me a description of herself1. - The full verb gave allows the reflexive pronoun to appear
- b. Sally1 gave me a description of her1. - The full verb gave allows the simple pronoun to appear.
The indices indicate coreference, i.e. the two coindexed words denote the same person. The reflexive pronoun must appear with the light verb, whereas the full verb allows the simple pronoun to appear as well. This distinction has to do with the extent of the predicate. The main predicate reaches down into the noun phrase when the light verb appears, whereas it excludes the noun phrase when the full verb is present.
Compositionality in terms of catenae
Light-verb constructions present the same difficulty associated with idiosyncratic expressions of every sort: the meaning is not compositional in a straightforward way. This fact is evident in the examples above, inasmuch as the words that constitute a light-verb construction often do not qualify as a constituent in any sense. These constructions do, however, form catenae (= chains). This fact is illustrated with the following dependency grammar trees:
The words of each light-verb construction form a catena. In this regard, the words in green qualify as the main predicate of the clause each time. If an auxiliary verb is present (as in trees b and d), it is included in the main predicate because like the light verb, it contributes functional meaning only.
Light verbs in other languages
Examples in other languages include the Yiddish geb in geb a helf (literally give a help, "help"); the French faire in faire semblant (lit. make seeming, "pretend"); the Hindi nikal paRA (lit. leave fall, "start to leave"); and the bǎ construction in Chinese. Light verbs are extremely common in Indo-Iranian languages, Japanese, and other languages in which verb compounding is a primary mechanism for marking aspectual distinctions. Light verbs are also equivalent to inherent complement verbs   in many Kwa languages e.g. jo in jo foi "run" Ga, tu in tu fo "advise" in Akan.
Light verbs are interesting to linguists from a variety of perspectives, including those of diachronic linguistics and computational linguistics. From the diachronic perspective, the light verb is said to have evolved from the "heavy" verb through semantic bleaching, a process in which the verb loses some or all of its original semantics. In this sense, the light verb is often viewed as part of a cline:
In computational linguistics, a serious challenge is that of identifying light verb constructions, which require marking light verbs.
- Concerning light verbs in general, see Jespersen (1965, Volume VI:117), Grimshaw and Mester (1988), and especially Butt (2003:paper atttached).
- The Collins Cobuild English Grammar, for instance, uses the term delexical verb instead of light verb.
- A light verb construction is a multiword expression that combines a light verb with another word or phrase, such as a noun phrase or preposition. See S. Stevenson et al. (2004).
- Concerning the status of constructions as catenae, see Osborne and Groß (2012).
- See Hornstein et al. (2005:99f.).
- Nwachukwu, P. A. (1985). "Inherent complement verbs in Igbo". Journal of the Linguistics Association of Nigeria 3, 61-74.
- Essegbey, James (1999). Inherent complement verbs revisited: Towards an understanding of argument structure constructions in Ewe. MPI Dissertation series 10.
- Adger, D. 2003. Core syntax: A minimalist approach. Oxford, UK: Oxford University Press.
- Butt, M. 2003. The Light Verb Jungle. In Harvard Working Papers in Linguistics, ed. G. Aygen, C. Bowern, and C. Quinn. 1–49. Volume 9, Papers from the GSAS/Dudley House workshop on light verbs.
- Collins Cobuild English Grammar 1995. London: HarperCollins Publishers.
- Grimshaw, J. and A. Mester. 1988. Light verbs and ɵ-Marking. Linguistic Inquiry 19, 205-232.
- Hornstein, N., J. Nunes, and K. Grohmann 2005. Understanding Minimalism. New York: Cambridge University Press.
- Jespersen, O. 1965. A Modern English Grammar on Historical Principles, Part VI, Morphology. London: George Allen and Unwin Ltd.
- Osborne, T. and T. Groß 2012. Constructions are catenae: Construction Grammar meets Dependency Grammar. Cognitive Linguistics 23, 1, 163-214.
- Steven, S., A. Fazly, and R.North. 2004. Statistical measures of the semi-productivity of light verb constructions. In 2nd ACL workshop on multiword expressions: Integrating processing, pp. 1–8.