Abstract: This article outlines why the treatment of idiomatic elements in language in terms of constructions can be considered real step forward in the understanding of the character of language. It is argued that construction grammar provides theoretical basis for accommodating insights into the phraseological character of language that were gained in number of fields such as corpus linguistics, foreign language teaching and traditional phraseology and lexicography.Keywords: Collocation, Corpus Analysis, Construction, Contextualism, Electronic Dictionaries, Exemplar, Foreign Language Teaching, Idiom Principle, Learner's Dictionaries, Lexicography, Probabeme, ValencyIntroductionConstructionsWill the beginning of the 21st century be looked upon by later historians of the subject as turning point in the history of linguistics? At any rate, there seems to be growing number of linguists who are attracted to theories sailing under such labels as construction grammar (Fillmore, 1988; Goldberg, 1995; 2006; Croft, 2013; Stefanowitsch, 2011a), usage-based approach (Tomasello, 2003; Bybee, 2010; Lieven, 2014) or cognitive grammar (Langacker, 1987; 2008a). These approaches (although, as indicated by the plural, by no means presenting unified theory) have emerged as sort of counterpoint to generative linguistics, i.e., the research instigated by the enormously influential ideas put forward by Noam Chomsky from the 1950s onwards. Both camps have in common that they explicitly address cognitive issues and that they are aiming at providing accounts of language acquisition, but they differ with respect to large number of issues (concerning modularity, the role of derivations, the learnability of language, to name just few).1Usage-based researchers such as Boas (2011: 55-60), Bybee (2010: 22-28), Goldberg (2013: 15) or Lieven (2014) imagine language to consist of network of constructions, which are stored in the constructicon on the basis of the input speaker has, with frequency of occurrence being relevant factor. The term construction has received number of different interpretations; commonly it is described as pairing of form and meaning, which is reminiscent of de Saussure's notion of the linguistic sign but, as Hoffmann (forthc.) points out, goes far beyond it. Goldberg (2006: 5) provides the following definition of construction:Any linguistic pattern is recognized as construction as long as some aspect of its form or function is not strictly predictable from its component parts or from other constructions recognized to exist. In addition, patterns are stored as constructions even if they are fully predictable as long as they occur with sufficient frequency.If we subscribe to Goldberg's (2006: 18) programmatic statement that it's constructions all the way down, in other words, that speaker's linguistic knowledge can be thought of entirely in terms of constructions, then it must be shown that all insights into the nature of linguistic phenomena can be accounted for in terms of constructions.2 If we want to demonstrate that Construction Grammar has useful contribution to make to the learning and teaching of foreign languages, then we must show that constructionist account of the linguistic phenomena central to foreign language learning provides us with insights that can be usefully applied to teaching methodology and the design of teaching materials.The present article attempts to do this with respect to the phenomena of collocation and valency in English, both of which cause problems to foreign learners and both of which have received considerable attention in monolingual learners' dictionaries, for instance.Constructing idiomsIdiomsIdioms in the classical sense present prototypical case of constructions. Traditional definitions of idioms usually employ criteria such as semantic opacity or restrictions on formal realizations3 and Cruse (1986: 37) characterizes an idiom as a lexical complex which is semantically simplex 4 . …