Haspelmath (2007) surveys coordination structures in the world's languages. He lists the following as logical possibilities for binary coordination. The examples are also taken from Haspelmath 2007. co here indicates the coordinator/conjunction.
- A B (widespread, e.g. Sarcee (Athapaskan; Canada), Maricopa (Yuman; Arizona), Kayardild (Tangkic; northern Australia))
- A co-B (English, Lango (Nilotic; Uganda))
- A-co B (Classical Tibetan)
- A B-co (Latin)
- co-A B unattested
- co-A co-B (Yoruba (Kwa; Nigeria))
- A-co B-co (Martuthunira (Pama-Nyungan; western Australia))
- A-co co-B (Homeric Greek)
- co-A B-co (Latin)
For the purposes of NLP, the distinction between "A-co B" and "A co-B" might be important for reasons of punctuation. For example in Arabic, the conjunction و wa is prefixed to the following word, without a space.
According to Haspelmath 2007, who cites Stassen 2001 as the authority, of the last four strategies, only "A-co B-co" seems to ever be used as a default, but it is widely-attested. "co-A co-B" is used only to contrast with "A co-B". The last two strategies are "extremely rare" (Haspelmath 2007) and the languages displaying them almost certainly have other strategies for coordination. For example, Latin has "A et B".
Moving to multiple coordination, Haspelmath 2007 provides the following useful chart of major patterns of correspondence between binary and multiple coordination:
Surprisingly, the pattern of coordinator omission "A-co B C D", though rare, is attested in Classical Tibetan and Amharic. It is also possible to omit all coordinators, leaving "A B C D".
For the purposes of NLP, then, to really handle all the possibilities, you would need to be able to specify what separators occur in the following positions, where A...Z are the nouns.
▓▓▓ A ▓▓▓ B ... M ███ N ... Y ███ Z ███
(A couple of notes: I've made the first two blocks lighter ▓▓▓ to show that supporting these is likely to yield marginal returns, as most (all?) languages would support alternate strategies for coordination. Also, this would not handle the Oxford comma, which treats lists of length 2 and >2 differently.)
Haspelmath, Martin (2007). Coordination. In Shopen, Timothy (ed.) Language typology and linguistic description, 2nd ed. Cambridge: CUP.
Stassen, Leon (2001). Some universal characteristics of noun phrase conjunction. In Plank, Frans (ed.) Noun phrase structure in the languages of Europe. Berlin: Mouton de Gruyter.