Nandi relatives and Arabic center-embedding

Two random interesting bits thrown up by my current research:

Nandi, a Nilotic language of Kenya with VSO order, would appear to allow you to relativize virtually any constituent of a sentence. I was particularly impressed by examples like:

nikò ce:pyó:sé:t ne â:-nken ci:tà ne kí:-ká:ci kitâ:pú:t
this woman Rel 1s-know person Rel Past-give book
"This is the woman that I know the person that gave [her] a book / that [she] gave a book to."

á-ké:r-é ci:tà ne pè:nt-í: àk la:kwe:-nyi: kâpsá:pit
1sg-see-impfv person Rel 3pl-go and child-his Kapsabet
"I see the person who [he] and his son are going to Kapsabet."

Take that, Subjacency Constraints! (Well, more seriously, I'm guessing ce/ne is probably not a fronted relative pronoun, especially since it agrees in case with the head noun and not with the position of the gap, so maybe no movement is involved - but that just raises other issues, like what does the gap consist of? Surely not pro? And what is ce/ne - a complementizer?)

And, in case you've ever wondered what an Arabic incomprehensibly double center-embedded sentence would look like, here's one:

رأى الولد الذي كتب الرجل الذي عينه الرئيس الرسالة إليه أخاه
ra'aa lwaladu lladhii kataba arrajulu lladhii `ayyanahu rra'iisu rrisaalata 'ilayhi 'axaahu
saw [the-boy [that wrote [the-man [that chose-him the president]] the letter to him]] brother-his.
“The boy the man the president chose wrote to saw his brother.”

Note that Arabic's VSO order renders it less vulnerable to subject- and object-relativization in this regard, but leaves it helpless against relativization of other positions - which is nonetheless permissible.

(Nandi examples from Creider & Creider 1989.)

Center-embedding and Japanese

Lately I've been reading some of John Hawkins' A Performance Theory of Order and Constituency, which puts forwards some very appealing ideas about how to predict the relative frequency of different word orders (both cross-linguistically and within a language) by quantifying how easy they are for humans to parse. (For example, he derives such phenomena as Heavy-NP shift, the relativization hierarchy, and even the relative frequency of the six possible basic word orders SVO/SOV, VSO, etc.) Parsing issues certainly severely affect the grammaticality of sentences, as people who follow titles posts Language Log authors write have know.

I tried out a similar example in Japanese on a friend - going by the grammar books, one would expect "John said Mary thinks Bill came" to be translated as "Jon-wa Merii-ga Biru-ga kita to omou to itta", with three successive subjects followed by three successive objects. She unhesitatingly went for, as I recall, "Biru-ga kita to Merii-ga omou to Jon-ga itta" - moving the subjects to the "wrong" places to make the sentence processable - and said that the three-successive-subject one was "difficult". I can't think of any Arabic parallels offhand - postverbal objects and resumptive pronouns in relative clauses together stop most of the obvious possibilities - and Sylheti turns out to rather cleverly block almost (not quite) all possible ways in which problematic center-embedding might emerge. So my question to you is: in your language, can you think of similar examples of incomprehensible yet nominally grammatical sentences?

Sylheti word order

I've been working on Sylheti - a highly divergent dialect of Bengali / language very closely related to Bengali spoken around Sylhet in northeastern Bangladesh - for my field methods class for a while. The particular point I'm focusing on at the moment is the positioning of complement clauses, which obeys a simple rule: if the complement clause has a separate subject, it follows the verb; otherwise, it precedes the verb. The language is otherwise SOV, I should note, so you get contrasts like:

ami exṭa apol sai.
I an apple want-1.
“I want an apple.”

ami exṭa apol xaitam sai.
I [an apple eat-COND-1] want-1.
“I want to eat an apple.”

ami sai he exṭa apol xaok.
I want-1 [he an apple eat-3-OPT].
“I want him to eat an apple.”

This doesn't fit my Japanese-based expectations of "proper" SOV languages (in Japanese, the subordinate clause would always precede the verb) but it turns out that German has basically the same word order (if you factor out the main-clause V2 order by having an initial complementizer). There are some obvious processing motivations for such an order, but it doesn't really fit the head-position parameter idea so well. I was wondering: has anyone seen similar patterns in other SOV languages?