R. S. Ginzburg, S. S. Khidekel, G. Y. Knyazeva, A. A. Sankin a course in modern english

-ish conveys likeness to the inner, most typical qualities of the object, -y in most cases conveys likeness to outer shape, form, size of the object. Suffixes -er, -ist both possess the meaning of the agent, but the distinguishing feature of the suffix -er is that it conveys the meaning of the active doer (animate or inanimate), whereas -ist conveys the meaning of profession (flutist, biologist) and followers of principles and beliefs (socialist, leftist) and thus has the meaning only of human beings. Derivational affixes semantically may be both mono- and polysemantic.

Derivational affixes are highly selective and each is applied to a specific set of bases which is due to the distributional type of meaning found in all affixes. All affixes are selective as to the structural peculiarities of bases (their morphemic, derivational, phonological and etymological features), some in addition are highly responsive to the lexical-semantic properties of the bases they are collocated with. For example, the adjectival suffix -able is collocated with verbal bases with practically no semantic constraints imposed on them. On the other hand the adjective-forming suffix -ful₁ is restricted in its collocability to nominal bases of abstract meaning (useful, beautiful), while its homonym the noun-forming -ful₂ also collocating with nominal bases chooses bases of concrete meaning and within this class only nouns which have in their semantic structure a semantic component ‘container’ (chestful, lungful, bagful).