Compensatory lengthening and The secret of time

No, I'm not about to go mystic on you, no worries. But time does come into it. Now - just humour me for a moment and enjoy:

V > V:; VV /_ C: [+son]#

V > V:; VV /_ C: [+son][αplace]C[αplace]

V > V / _ C:[+son]V

V > V / _ C:[+son][αplace]C[βplace] and α ≠ β

You know, when I started doing linguistics ... quite some time ago, I thought I'd finally escape maths. Hah! Anyway, that was just for enjoyment, I will make things much clearer.

I'm sure you have all come across words like ann, ball, ceann and cam and wondered where the strange diphthongs come from? So why do we say [auN] and [kaum] and [bauL] rather than *[aN], *[kam] or *[baL]? Ok, we can take the view that they simply are pronounced like that and that we have to learn by listening. Fair enough, listening is important but some of us are a bit more inquisitive than that and we don't all have the privilege of living with a native speaker. And as it turns out, there are a few very good pointers - less arcane than the above rules by the way.

So here's what happened: Going back to Old Irish (again), we find a handful of interesting consonants. Long sonorants - that is, long l n r and m. They are called sonorants because you can "keep saying them", almost as if they were vowels, something that doesn't work with p t k for example. Because they were long, our kind scribes wrote them as double consonants, quite logical really. So we got

Old Irish	Gaelic	Irish
lomm [Lomː]	lom	lom
tomm [tomː]	tom	tom
mall [maLː]	mall	mall
mell [mʲeLː]	meall	meall
cenn [kʲeNː]	ceann	ceann
donn [doNː]	donn	donn
corr [koRː]	corr	corr
cerr [kʲeRː]	cearr	cearr

So what? Well, it turns out long consonants are prissy, pardon, unstable sounds which don't hang around for long. What often happens is that the long consonants "transfer" their long quality to the preceding vowel. This in turn gets broken (diphthongised) in many cases. That happens in many languages, just think of the changes from Old English to Modern English: hlūd [luːd] became loud [laʊd], nama [naːmə] became name [neɪm]). The pronunciation daisy chain goes like this from Old Irish to Gaelic:

Old Irish ⇨	Middle Irish ⇨	Common Gaelic ⇨	Scottish Gaelic (most)
lomm [lomː]	lom [loːm]	lom [loːm]	lom [lɔum]

If the sonorant is followed by another vowel, this doesn't happen. This includes words with helping vowels, so words like Donnchadh escape both lengthening and diphthongisation. This is called "rule ordering" in linguistics, meaning that when you have two rules which could both apply, the language usually has a preference for which applies first and which second. Usually, applying one means the other can't apply any more.

A good pair of words to remember here is caill [kaiLʲ] and cailleach [kaLʲax]; similarly ann [auN] and Anna [aNə].

This happens in virtually all surviving dialects. Some conservative (regarding lengthening) dialects of East Perthshire, Kintyre and Arran had kept the long consonants and never lengthened the vowel or broken but they are mostly moribund today. So to be brief, all that needs to be said about these dialects is that in almost all cases these dialects either lengthen the vowel or simply have a short vowel, but hardly ever dipthongise. So in Arran Gaelic for example ann, ceann, donn, cum and ionnsaich would be pronounced as: [aN] [kʲaN] [doN] [kum] and [iNsiç], around Cowal this would be [aNː], [kʲaNː], [doNː], [kumː] and [iNːsɪç].

The most lively dialects today are fairly homogeneous, except perhaps for Lewis Gaelic (don't sigh) which is the most progressive amongst these but we'll deal with that later.

before ll	before nn	before m	before rr
a
call [kauL]	gann [gauN]	cam [kaum]	barr [baːR]
(e)ai
caill [kaiLʲ]	cainnt [kãĩNʲdʲ]	maim [maim]	feairrd [fjaːRdʲ]
ea
seall [ʃauL]	ceann [kʲauN]	dream [draum]	cearr [kʲaːR]
ei
beinn [beiNʲ]	greim [grʲeim]
i
cill [kʲiːLʲ]	binn [biːNʲ]	im [iːm]
io
	fionn [fjuːN]		sgiorr [sgʲu:R]
iu
		rium [rʲuːm]	tiurr [tʲuːR]
o
toll [tɔuL]	fonn [fɔuN]	tom [tɔum]	torr [tɔːR]
oi
goill [gɤiLʲ]	roinn [RɤiNʲ]	stoim [sdɤim]
u
a-null [əˈNuːL]	grunn [gruːN]	cum [kuːm]	sgurr [sguːR]
ui
tuill [tɯiLʲ]	cluinn [kLɯiNʲ]	druim [drɯim]

Lewis just extends the breaking to [iː] and [uː] so you get cum [kɔum] and ìm [ɤim] etc.

So how does this all relate to the Secret of Time? What's Gaelic for time? Àm, isn't it? Or is it am? Cùm or cum? Ceàrr or cearr? Strictly speaking, as long as you are aware of the rules of lengthening/diphthongisation (which is easy if you're a native speaker - and now for you as you know the rule) there is no need really to indicate length over the vowels. Whatever GOC says, it's up to you in a way because the grave is surplus to requirements. But that's the secret behind this confusion over words like àm vs am anyway.

Watch out for the derivatives of these words though. Remember that a following vowel prevents a long vowel or a diphthong from appearing. So as many words add a vowel to indicate the genitive or add an ending to form a verbal noun, you must not pronounce or write a long vowel/diphthong in the derived word. Here's a few illustrative examples:

àm	⇨	clàr-ama, amannan...
barr	⇨	Dùn Bharra, barrachd...
gearr	⇨	a' gearradh, a ghearras, gearraidh...
ceann	⇨	a' ceannach, a cheannaicheas...
cum	⇨	a' cumail, a chumas, cumaidh...
tinn	⇨	nas tinne, tinneas...

My person recommendation is that you don't use it, it just messes up stuff, especially for learners but I've even heard to odd native speaker get this pearshaped when reading a text out loud. The only exceptions are:

• words which always have a long vowel/diphthong (féill, dìlleachdan, ciùrradh, ciùrrail...)
• two letters words like ìm and àm, technically not necessary either but that is a usage that is fairly old, presumable because of the potential overlap between the definite article and àm.

So in a nutshell:

A vowel before ll nn rr and m will get lengthened or diphthongised except if is followed by a vowel

So. Happy diphthongising to you all.