Ўзбекистон республикаси олий ва ўрта махсус таълим вазирлиги ўзбекистон давлат жаҳон тиллари университети инглиз тили назарий аспектлари №1

Partially motivated word-groups – where the meaning of at least one component helps to distinguish the meaning of the whole, e.g. to shrug one’s shoulders, to fall in love.
Non-motivated word-groups – where the meaning of the whole cannot be guessed (drawn) from the meanings of their components, e.g. red tape – ‘official bureaucratic methods’, heavy father – ‘serious or solemn part in a theatrical play’, and take place — ‘occur’.
A phraseological unit is a stable word-group characterized by a completely or partially transferred meaning and structural and functional inseparability. They can not be freely made up in speech but are reproduced as ready-made units, characterized by stability of the lexical components and lack of motivation.