o in a final unaccented syllable predominates over a preceding e in
the same syllable. Therefore, _óleo_ and _erróneo_ assonate in ó-o;
but o in a final unaccented syllable is dominated by a following e in
the same syllable, and the e counts in the assonance. Therefore,
_héroe_ and _veces_ assonate in é-e.

When two weak vowels (i, u) are united in a diphthong, the second
predominates. Thus _triunfo_ and _chulo_ assonate in ú-o; _cuido_ and
_bendito_ assonate in i-o.

There are twenty possible assonances in Spanish: á, ó, é, i, ú, á-a,
á-e, á-o, é-a, é-e, é-o, ó-a, ó-e, ó-o, i-a, i-e, i-o, ú-a, ú-e, ú-o.

Words that have in the final unaccented syllable i or u, not in
diphthongs, are considered for purposes of assonance as if ending in e
or o respectively. Therefore, _fácil_ and _nave_ assonate in á-e;
_espíritu_ and _líquido_, in i-o.

If ai occurs in a syllable after an a in the accented syllable, the i
rather than the a of the diphthong counts in the assonance. Therefore,
_cantares_ and _trocabais_ assonate in á-e. If the accented vowel is
not a, the a of ai counts in the assonance. Therefore, _Vicenta_ and
_quisierais_ assonate in é-a.

Consonantal rhyme should not be introduced in compositions written in
assonance. This rule is not always observed (see pp. 183-184, LIII).

The assonance of alternate lines (the even numbers) is the rule in
modern Spanish. If the composition is short the same assonance may be