The Latin diphthong an is rendered in Portuguese by ou (euro, a u r u mu; pouco, p a u c ii m), also pronounced of.
H is merely an orthographic sign; it is used to indicate that two consecutive vowels do not form a diphthong (vehs raho), and, added to c, it denotes the pronunciation of the guttural c at the end of a word (arnich).
Latin au becomes o (cOla, c a u s a; or, a U r u m); Old Catalan has kept the diphthong better, but possibly we- should attribute the examples of au which are met with in texts of the 13th and 14th centuries to the literary influence of Provence.
In some cases a post-tonic vowel other than a is preserved in Catalan, as, for example, when that vowel forms a diphthong with the tonic (Deft, D e us; Ebriu, He bred s); or, again, it sometimes happens, when the tonic is followed by an i in hiatus, that the i persists (diliivi, dilfivium; servici, servicium; lbi, lbium; ciri, cereus); but in many cases these ought to be regarded as learned forms, as is shown by the existence of parallel ones, such as servey, where the atonic i has been attracted by the tonic and forms a diphthong with it (servIci, scrvii, serve)?).
Latin e was identified with a native diphthong ei, and becomes zvy, as in rhwyf from remus.
The diphthong ai is 1 K.
Words beginning in hue, where the Ii, not etymologically derived, marks the inseparable aspiration of the initial diphthong ue, are readily pronounced ge throughotit almost the whole extent of the domain: gziele for huele (o I e t); gueso for hueso (0 s).