Re: Diphthongs in Lojban

la matius. cusku di'e

> 1.  Can the "second-class" diphthongs (ia..iu, ua...uu) be used in le'avla?

Yes.  However, no two le'avla may differ solely on the differential assignment
of diphthongs: thus "*bloi,o" and "*blo,io", though both valid le'avla, cannot
be both in use.  By default, "*bloio" means "*bloi,o".  In addition, le'avla
like "*bloi,io", with two consecutive diphthongs, are discouraged.

> 2.  Is the restriction of diphthongs in normal words to ai, au, ei and oi
>     purely historical?  How about the complete non-use of eu, ao etc.?

I wasn't there when the decision was made, but I understand that it was
basically intended for ease of use.  I personally would have permitted "eu"
as well, but many people have trouble saying it.

Loglan did not (and does not) have "'" at all; there are 25 diphthongs with
rules about which are to be pronounced as monosyllables, which as disyllables,
and which are variable.  Furthermore, "aa", "ee", and "oo", which are
disyllabic, could only be used where one of the syllables bears the word stress.

The introduction of "'" made all 25 diphthongs sayable as disyllables, and
distinct from any retained monosyllables.  Monosyllabic diphthongs add
nothing except brevity and greater cmavo/rafsi space; 4 apparently seemed
like a reasonable tradeoff against increased pronunciation difficulty.

-- 
John Cowan		sharing account <lojbab@access.digex.net> for now
		e'osai ko sarji la lojban.