"Какая рогастая, глазатая, ушатая корова!" — or the morphological domains of "-ст-" vs. simply "-т-"

Question

Perhaps you've noticed this before (every non-native speaker certainly has):

• носатый
• волосатый
• рогатый
• усатый
• хвостатый
• полосатый

but:

• губастый
• мордастый
• рукастый
• ушастый
• глазастый

What is the pattern here? Is there one?

Before you hurry to reject my very premise: I am of course perfectly aware that for some, or perhaps even many, of these, both alternatives exist (e.g. хвостастый is not unheard of, and Глазатый happily thrives at least as a family name). It's just that one always wins out considerably over the other. But is there any explanation for which one wins when?

I am also aware of pairings such as зубастый кит vs. зубатый кит, which simply mean entirely different things. But again, is there a reason why they mean these things in that order — and not exactly the other way round?

In short: is there any rhyme and reason behind some adjectives being created using "-ст-", and others using a simple "-т-"? Or is this something like -ic- vs. -ical- in English, where no clear pattern exists at all and everything is left entirely to chance?

Answer 1

It should be quite obvious for native speaker, that -аст- and -ист- are augmentative suffixes.

Let we take for example the word усы (moustache). Since not everyone has it there is a common adjective усатый, which stands for somebody who simply has moustache. But there is also less common word усастый. It’s suitable for somebody who has very large (or notable for other reason) moustaches.

This makes clear the difference between зубатый кит & зубастый кит. Зубатый кит (toothed whale, this is a biological term) unlike other whales has teeth. Зубастый кит (this is an epithet) is quite toothy whale.

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Довольно очевидно для носителя языка, что -аст- и -ист- — это увеличительные суффиксы.

Возьмем для примера слово усы. Поскольку не каждый их носит, широко распространено прилагательное усатый, означающее, что некто просто носит усы. Но есть и менее распоcтраненное слово усастый, подходящее для человека с большими (или примечательными по иной причине) усами.

Отсюда понятна разница между зубатым и зубастым китом. Зубатые киты (это термин), в отличие от остальных, просто имеют зубы. Зубастый же кит (это эпитет) зубаст весьма.

Answer 2

I want to add to the answer by Dmitry Alexandrov some information about the origins of the suffixes. The suffix -аст-, -ист- comes from Proto-Indo-European superlative suffix -isto- while -т- comes from PIE adjectival suffix -to-. So the both retain their meanings to an extent, although the former is usually used as augmentative rather than superlative in Russian.

For instance, in PIE we have:

a̯rtos - fitting

a̯ristos - of the best sort

ğra̯utos - heavy

ğra̯u̯istos - heaviest

A derived superlative suffix one can observe in English, the -est. For instance, in the word longest (< PIE dlonghistos).

Answer 3

As a general rule, it seems, adjectives with -т- mean that a specific feature is [noticeably] present, and -ст- means that a feature is prominent.

Obviously, носатый is an exception. Волосатый is used both ways: волосатая грудь (a breast that has [noticeable] hairs while as opposed to a breast without [noticeable] hairs) vs волосатый юноша (a young man whose hair-do is more prominent than most men have).