PARADIGMATIC AND SYNTAGMATIC. Contrasting terms in (structural) LINGUISTICS. Every item of language has a paradigmatic relationship with every other item which can be substituted for it (such as cat with dog), and a syntagmatic relationship with items which occur within the same construction (for example, in The cat sat on the mat, cat with the and sat on the mat). The relationships are like axes, as shown in the accompanying diagram.

			syntagmatic
	The	cat	sat	on	the	mat.
paradigmatic	His	dog	slept	under	that	table.
	Our	parrot	perched	in	its	cage.

Paradigmatic contrasts at the level of sounds allow one to identify the phonemes (minimal distinctive sound units) of a language: for example, bat, fat, mat contrast with one another on the basis of a single sound, as do bat, bet, bit, and bat, bap, ban. Stylistically, rhyme is due to the paradigmatic substitution of sounds at the beginning of syllables or words, as in: ‘Tyger! Tyger! burning bright / In the forests of the night.’

On the lexical level, paradigmatic contrasts indicate which words are likely to belong to the same word class (part of speech): cat, dog, parrot in the diagram are all nouns, sat, slept, perched are all verbs. Syntagmatic relations between words enable one to build up a picture of co-occurrence restrictions within SYNTAX, for example, the verbs hit, kick have to be followed by a noun (Paul hit the wall, not *Paul hit), but sleep, doze do not normally do so (Peter slept, not *Peter slept the bed). On the semantic level, paradigmatic substitutions allow items from a semantic set to be grouped together, for example Angela came on Tuesday (Wednesday, Thursday, etc.), while syntagmatic associations indicate compatible combinations: rotten apple, the duck quacked, rather than *curdled apple, *the duck squeaked.