For example, the expanding relation of ‘addition’ may be realised
(1) cohesively by a conjunction such as also or
(2) structurally by
(a) an additive paratactic clause complex marked by the structural conjunction and,
(b) a circumstance of accompaniment marked by the preposition with or
(c) an additive paratactic group complex marked by and … .
These realisational variants are distinct in the grammar, since they constitute different grammatical environments; but they are semantically agnate in that they all have the feature of ‘addition’. … One semantic system, the system of expansion, has thus evolved to bring together patterns of wording within grammatically distinct units, thereby extending its overall meaning potential.