Halliday & Matthiessen (2014: 643-4):
The primary types of lexical relations are listed in Table 9-17. They derive from either the paradigmatic or the syntagmatic organisation of lexis. (i) The paradigmatic relations are inherent in the organisation of lexis as a resource, as represented in Roget’s Thesaurus. They can be interpreted in terms of elaboration and extension, two of the subtypes of expansion … . (ii) The syntagmatic relations hold between lexical items in a syntagm that tend to occur together, or collocate with one another. Collocates of a lexical item can be found in the entries of certain modern dictionaries based on corpus investigations. Since syntagmatic organisation and paradigmatic organisation represent two different dimensions of patterning, any pair of lexical items can involve both.
⁹ Collocation includes, but is not confined to, relationships that can be interpreted as enhancing.
