c. Pairs of a strong vowel plus a weak vowel
{ ai, au,
{ ei, eu,
{ oi, ou.
d. Pairs of a weak vowel plus a strong vowel
{ ua, ue, uo,
{ ia, ie, io.
NOTE: In diphthongs a dominates o and e; and o dominates e. Any strong vowel dominates a weak one.
Ex. In Bo^abdíl, if a were not dominant, the diphthong would be dissolved.
2. DIPHTHONGS AND WORD ACCENTUATION
There are with regard to accent three possible conditions under which two contiguous vowels may occur within a word.
a. The contiguous vowels may precede the accented syllable.
b. One of the contiguous vowels may be accented.