How do native speakers know which morphological variations are possible in cases where word-evidence is sparse?

In this interesting answer to a 4 year old question (which, ironically, I found by browsing unpopular questions on Meta), we find this tidbit:

Just as in Japanese, not only is the "non-native" stratum considered more erudite than the native one, there are grammatical differences between the strata (although fewer than there are in Japanese). For instance, the suffix -ate or -ation in English can only directly attach to a Latinate word, e.g. vary -> variation, but not bury -> *buriation.

What's interesting about it is I know the assertion to be true, but before reading this answer I could not have told you the etymology of the two words. I did not know vary is derived from Latin and bury from proto-Germanic. But I did know that not only was buriation "not a word", but it could not be one, despite the fact that I am more or less ignorant of the rules of English morphology.

That is, I am ignorant in the "explicit knowledge" sense, but obviously since I know buriation can't be a word, I have some tacit knowledge that I could never voice.

But how is that? What is it about bury, as opposed to vary, that tells me buriation could not be a word? I don't mean the decades of exposure and practice I have with English that tells me it isn't a word, but that morphologically speaking, it couldn't be.

Is there a more general rule at play here, something morphological as opposed to etymological? Are there more examples in this category?

Solution 1:

I think there are a variety of reasons why *buriation seems wrong.

Blocking by burial

We already have the noun burial that basically refers to "an event of burying" or "the act of burying" or "the result of burying." This occupies a lot of the same semantic space that I expect would be filled by a noun *buriation.

There's a general concept that it's harder to form new words when there's an existing word that already means the same thing. It's called blocking.

From Morphology: Word Structure in Generative Grammar, by John Thayer Jensen:

[Blocking] is quite general. For example Aronoff (1976, 43-5) shows that adjectives in -ous do not form derivative nouns in -ity if a noun with the presumed meaning exists independently; curious gives curiosity but glorious does not give *gloriosity because of the existence of glory.

As can be seen from this example, blocking actually affects words of Latin origin as well, so it doesn't require previous knowledge of where words like bury came from. It's basically like you said in your comment: "We have burial already, don't let's get greedy."

"Vary"~"variation" is not a common derivational pattern

V0ight already pointed this out, but if we look at the set of nouns ending in -iation, we see that the majority of them are derived from verbs ending in -iate. Variation is actually the only one I can find that is related to a verb ending in -y. (Some other odd ones are those ending in -nunciation, with verbs in -nounce, and spoliation, which goes with the verb spoil).

The word "vary" has a network of other suffixed Latinate forms

There are many other words related to vary that have Latinate suffixes, which might give people some subconscious awareness that it can be used with this class of suffixes.

For example: variant, variance, variety, variegate, various.

No related words like this exist for bury.

Solution 2:

I think the answer to this seemingly complicated question is in fact very simple: bury and vary are simply two very unique words and the fact that one is able to be conjugated to a noun form of iation is a mere coincidence that has little to do with its Latin roots.

If we examine the number of verbs ending in -ary, only two come up: vary and the rarely used verb weary/overweary: OneLook reverse dictionary

If we examine the number of verbs ending in -ury, only one comes up: bury/rebury: OneLook reverse dictionary

So the fact that you were able to guess that bury couldn't possibly have a noun form ending in -iation wasn't due to its Germanic origins, but more due to the fact that there are few verbs ending in -ry that conjugate to -iation in the first place.