Free word groups and phraseological units

I. There are two factors which are important in uniting words into word-groups:
– the lexical valency of words;
– the grammatical valency of words.
Lexical valency is the ability of a word to be used in different lexical contexts i.e. in combinations with other words., e.g., V + N – to deliver letters = “to distribute letters,” To deliver a blow = “to strike a blow,” To deliver a lecture = “to give a lecture”. The noun question is often combined with such adjectives as vital, pressing, urgent, delicate, etc. The aptness of a word to appear in various combinations is described as its lexical valency.
All free word-groups are formed on definite lexico-grammatical patterns. The pattern is an arrangement of component elements of a collocation. The patters of free word-groups are generative, i.e. any word in a sentence may be replaced by its synonym or hyponym: Brave (courageous, valiant, fearless, bold) man (woman, boy). But the range of the lexical valency of words is delimited by the inner structure of the English words. Thus, to raise and to lift are synonyms, but only the former is collocated with the noun question. The verbs to take, to catch, to seize, to grasp are synonyms, but they are found in different collocations: to take – exams, measures, precautions, etc.; to grasp – the truth, the meaning. Words habitually collocated in speech tend to form a cliche.
Words are also used in grammatical contexts. The minimal grammatical context in which the words are used to form word-groups is usually described as the pattern of the word-group. E.g., the adjective heavy can be followed by a noun (A+N) – heavy food, heavy storm, heavy box, heavy eater. But we cannot say «heavy cheese» or «heavy to lift, to carry», etc.
Grammatical valency is the ability of a word to appear in various grammatical structures; it is determined by the part of speech the word belongs to.
The grammatical valency of words may be different. The grammatical valency is delimited by the part of speech the word belongs to, e.g., no English adjective can be followed by the finite form of a verb.
The grammatical valency distinguishes individual meanings of a polysemantic word, i.e., , V + N – to grow roses (wheat) = “to cultivate”, V + V – to grow to like = “to begin”, V + A – to grow old (tired, dark) = “to become”, V + D – to grow quickly (rapidly) = “to increase”
The grammatical valency of the words belonging to the same part of speech is not necessarily identical, it may be delimited by the inner structure of the language, e.g. to suggest, to propose are synonyms, both can be followed by a noun, e.g., to propose (suggest) a plan, but it is only "propose" that can be followed by the infinitive of a verb – to propose to do something. Clever and intelligent have the same grammatical valency, but only clever can be used in word-groups having the pattern A+prep+N – clever at maths.
The range of grammatical valency is restricted by lexical valency: A + N – blind people (+) – blind sugar (-). A smiling girl (+) – a smilimg crocodile (-). But phrases, literally absurd, may be used figuratively: Look at him! A smiling crocodile!