OF THE DIPHTHONGS.
There are thirteen Diphthongs reckoned in Gaelic; ae, ai, ao, ea, ei, eo, eu; ia, io, iu; oi; ua, ui. Of these, ao, eu, ia, ua, are always long; the others are sometimes long, sometimes short.
Ae.
The sound of ae is made up of (1) a long, and (1) e short. This diphthong hardly occurs, except in Gael a Gaul or Highlander, and Gaelic the Gaelic language[[8]].
Ai.
The sound of ai is either made up of the sounds of both the vowels, or like that of the former.
1. Made up of (1) a and (1) i: the a long, the i short; as, fàidh a prophet; the a short, the i short; as, claidheamh a sword.
2. Made up of (2) a and (1) i: the a long, the i short; as, saighde arrows.
Before a Lingual or a Palatal, not quiescent, the i often loses its sound, and only serves to qualify the sound of the following consonant[[9]]; hence,
3. Like (1) a alone: long, as, fàisg squeeze, fàilte salutation; short, as, glaic a hollow, tais soft.