Fòram na Gàidhlig

Tha mi air a bhith glè thrang mo “Bhlas na Gàidhlig” agus “Gàidhlig Uidhist a Deas.” A dh’aindeoin, tha duilgheadas mòr fhathast a'm gu “consonant clusters” -rC, gu sònraichte R + fuaim chaol.
Tha an chiad leabhar ag ràdh gu bheil dualchainntean ann aig a bheil fuaimean “retroflex” an àite [R] ann an “consonant clusters” -rC (td. 231), agus dualchainntean aig nach eil diofar eadar, mar eisimpleir, tort agus toirt [tʰɔRst] (td. 318). A bheil dualchainnt ann aig a bheil an dà fheart (tort is toirt = [tʰɔʂʈ], bùrd is bùird = [buːʈ])? Dè an dualchainnt am b' e?
Canaidh mise:
airson: [ə(ɻ)ʂɔn]
àrd: [aː(ɻ)ʈ]
àirde: [aːɻtʲə] neo [aːRtʲə]
bùird: [buː(ɻ)ʈ] (’s urrainn dhomh [buːʂtʲ] fhuaimneachadh cuideachd. Am biodh nas fheàrr?)
càrn agus càirn: [kʰaː(ɻ)ɳ]
A bheil sin gu math nàdarra? Ciamar a bu choir fhuaimneachadh am faclan mar sin?
Mìle taing!

The above in English:
I have been very busy with my “Blas na Gàidhlig” and “Gàidhlig Uidhist a Deas.” However, I still have a lot of trouble with -rC clusters, especially with slender consonants. The first book states that there are dialects with retroflex consonants instead of [R] in -rC consonant clusters (pg. 231), and dialects without a difference between, for example, tort and toirt [tʰɔRst] (pg. 318). Is there a dialect with both features? Which dialect would it be?
I am in the habit of saying:
airson: [ə(ɻ)ʂɔn]
àrd: [aː(ɻ)ʈ]
àirde: [aːɻtʲə] or [aːRtʲə]
bùird: [buː(ɻ)ʈ] (I can also pronounce [buːʂtʲ]. Would that be better?)
càrn agus càirn: [kʰaː(ɻ)ɳ]
Is this natural Gaelic? How should I pronounce words like these?
Thanks so much!

You mean whether you can only have retroflex ɳ if you drop the ɻ or if you can have the whole cluster retroflex ɻɳ? Yes, you can have the whole cluster ɻɳ. That would be specific dialects but simply variation depending on lots of things. As a rule of thumb, if a dialect has [buːɳ] then [buːɻɳ] will also occur and lots of fine variations in between. It's like saying there's public transport that will take you from Edinburgh to Glasgow - this is true but you could take the bus or the train and you may end up at Buchanan Bus Station instead of Queen's Street.

In Blas, I tend to describe the "cardinal points" if you will in order not to go into way too much detail. Sometimes that means someone looking for all the detail won't find it, not in Blas anyway. Marbh leis is marbh as aonais

If you are aiming for South Uist in particular, I guess your best bet is to search Tobar an Dualchais for speakers from that are and have a listen. Of course, you will need to train your ears so that you will hear the difference.

Thank you both for your replies.
I apologize for being insufficiently clear, what I meant to say is how do dialects with r-dropping handle pairs like bòrd and bòird? If the r in bùirn were dropped bòird would either merge with bòrd or bòid.

Sorry for the late reply.

Bòird isn't really a common genitive or plural. Mostly it's bùird. So mostly it's Lewis Gaelic which allows turning r clusters into retroflexes and the rule of thumb is you take out the r and turn the following n or d into a ɳ or ɖ. So /buːɻɳ/ becomes /buːɳ/ and bòrd /bɔːɻɖ/ becomes /bɔːɖ/. In a slender cluster, you get the intrustive ʃ i.e. it's bùird /buːɹʃdʲ/ » /buːʃdʲ/. Not sure if you get any retroflex quality on the ʃ, quite possibly.

It's called rule ordering i.e. the rule that adds /ʃ/ in rd clusters takes precedents (in Lewis) over the deletion of r.