Modification can be considered a high-level domain of the functions of language, on par with predication and reference.
For example: In this noun phrase, man is the head, nice and tall are premodifiers, and from Canada and whom you met are postmodifiers.
In some other languages, words other than modifiers may occur in between; this type of situation is especially likely in languages with free word order, and often agreement between the grammatical gender, number or other feature of the modifier and its head is used to indicate the relationship.
[3] Two common parts of speech used for modification are adjectives (and adjectival phrases and adjectival clauses), which modify nouns; and adverbs (and adverbial phrases and adverbial clauses), which modify other parts of speech, particularly verbs, adjectives and other adverbs, as well as whole phrases or clauses.
For example: Here the participial phrase sitting on the step may be intended to modify her (meaning that the painting's subject was sitting on the step), or it may be intended to modify the verb phrase painted her or the whole clause he painted her (or just he), meaning in effect that it was the painter who was sitting on the step.