Before getting to the main content of today, I'll give some updates about things I am working on:
Currently, I am working on three main conlanging-related projects, two of these being conlangs, the third being a tool for conlangers. The two conlangs, however, rely on the tool being workable, and it is as of yet in a bit of a planning stage. Until it is done, this blog will probably not be updated very often. Expect maybe half a year for the unveiling of the tool, depending on work, other hobbies and other inconveniences. Let's set a deadline at Hannukkah 5781. Another conlang-related tool is in the early early planning stages, but will probably not see the lights of day until 2021.
In addition, I am coding a microtonal pitch perception webapp; it is still in its early alpha test days (and due to getting a new, more challenging job and a dog last january, I have not had much time to update it over the last year or so, the alpha test period really got out of hand!)
Also, I've been doing a fair share of duolingo in recent months, and if you don't already use it, I would definitely recommend it!
But ... on to linguistics!
It is not unusual for languages to permit leaving a gap when coordinating things in some kind of subordinate construction:
I eat and _ sleep.
They both saw _ and heard you.
He spent some time in Germany and _ Austria.
You are a good singer, both with _ and without amplification.
Now... we can imagine restrictions on this, and I am thinking of a few interesting ones.
1) Gender and Number Restrictions
One could imagine a restriction whereby any two nouns after a preposition need to be of the same gender and number - otherwise, the preposition needs to be repeated before the next noun(s).
This could even cut into subsets of the genders - one could require the same animacy as well. Also, some genders might be "closer" related to others, so e.g. masculine and neuter in German could maybe work?
2) Case
This gets a bit trickier, and mostly applies in languages with a case system like that of conservative IE languages. The cases of both nouns have to have the same distribution in the paradigm. Here, I mean a rather odd sense of what a case is: a case is an ending. In Russian, the feminine dative has the same suffix as the feminine prepositional, and thus, they'd be the same case here - and maybe we could accept masculine prepositionals to coordinate with feminine prepositionals, because they take the same suffix as well. But masculine datives and feminine datives would be an odd mix, due to the masculine datives being distinct.
In the case of Russian, this would allow animate masculine nominatives and feminines to co-ordinate (because, although these are different suffixes, the suffixes have the same *distribution*), and it would let masculine and feminine instrumentals to co-ordinate, because their suffixes also have the same distribution.
Case, however, lets us also think about coordination of verbs and prepositions: only those that take the same type of case on their object can allow gaps over coordination.