In final syllables the diphthongs ai, ei, oi, all appear as e.
Navarrese-Aragone~e has the diphthongs Ce, ue from tonic and, and adheres more strictly to them than normal Castilian doescuende (c b m i t e rn) huey (h d 1 e), pueyo (pb di U rn), yes (e s t), yeran (h r ii n t), while Castilian says conde, hoy, poyo, es, ryan.
On the other hand, Portuguese has a large n.urnber of strong diphthongs produced by the attraction of an i in hiatus or the resolution of an explosive into i: raiba (r a b I a),feira (fer i a), frito (f a c t u m), seixo (sax u m), osto (oct 0).
It is stated, for example, that Gallego does not possess nasal diphthongs; still it may be conceded once for all that such a word as p 1 a n u s, which in Galician is written sometimes chau and sometimes c/ian, cannot be very remote from the Portuguese nasal pronunciation chao.
In English, moreover, the vowel sounds tend to become diphthongs, so that the symbol for the simple sound tends to become the symbol for that combination which we call a diphthong.