(1) If one of two strong vowels (_a_, _e_, _o_) coming together has the
accent, they do not form a diphthong, and therefore do not count as a
single syllable in the verse. Dissyllables, for example, are _Jaén_,
_nao_, _leal_, _león_; trisyllables are _azahar_ (_h_ mute), _creemos_,
_canoa_.
Exceptionally, the two strong vowels are contracted: e.g., Samaniego has
contracted them in the hendecasyllable,
El l[eó]n, rey de los bosques poderoso,
and Espronceda in a tetrasyllable,
Y no hay playa
S[ea] cualquiera, _etc._
This contraction, called _synæresis_, is less harsh when the unaccented
vowel is _e_. It is frequent, however, with the first two vowels of
_ahora_.
(2) If two vowels come together, the first strong (_a_, _e_, _o_) and
the second weak (_i_, _y_, _u_), and if the accent rests on the strong
vowel, they regularly form a diphthong and count as one syllable; e.g.,
_c[au]to_, _p[ei]ne_, _f[eu]do_, _conv[oy]_, _r[ey]_, _s[oy]_. The
dissolution of this diphthong constitutes a very violent poetical
license. When it occurs it is termed _diæresis_ and is sometimes marked
by the dots so called; e.g., _glorïoso_, _suäve_.
(3) If the first of the contiguous vowels is strong, and the second weak
and accented, they form separate syllables, as in _raíz_, _baúl_,
_roído_. Contraction (_synæresis_) is rare and harsh in such cases: cf.
Meléndez Valdés in the hendecasyllable,
C[aí]do del cielo al lodo que le afea.
(4) If the first of the contiguous vowels is weak and the second strong,
and the accent is on the weak vowel, they naturally constitute separate
syllables, as in _día_, _río_, _valúa_, _lloraríamos_.
Synæresis is more frequent and less harsh here than in (3); cf.
Garcilaso:
Que hab[ía] de ver con largo acabamiento.
Espronceda:
Los r[ío]s su curso natural reprimen.
(5) If the first of two contiguous vowels is weak and the second is
strong and accented, the vowels sometimes form one syllable and
sometimes do not. Etymological conditions often determine the case; thus
_fió_ is a dissyllable, since it comes from a Latin source (_fidavit_)
in which the _i_ was in a syllable by itself, and _bien_ is a
monosyllable, since the _i_ and _e_ form a diphthong evolved out of a
single Latin vowel (the _ĕ_ of _bĕne_).
The chief cases are as follows:
(a) _iè_ and _uè_ from Latin _e_ and _o_ form diphthongs absolutely
indissoluble: _d[ie]nte_, _m[ue]rte_.
(b) In conjugation, analogy plays a part, and _fiamos_ follows _fiar_
(with the _i_ and the _a_ in distinct syllables), _cambiamos_ follows
_cambiar_ (with the _i_ and the _a_ in the same syllable).
Synæresis readily takes place for vowels ordinarily in distinct
syllables (_fió_, etc.); but diæresis hardly obtains for the vowels of a
true diphthong (_cambió_, etc.).
(c) The combinations _ió_ and _iè_ are usually diphthongs in the
terminations of the preterite indicative, the future subjunctive, the
past tenses of the subjunctive, and the gerund, of verbs of the second
and third conjugations: e.g., _mur[ió]_, _mur[ie]re_, _mur[ie]se_,
_mur[ie]ra_, _mur[ie]ndo_. In _rió_, _deslió_, _rieron_, _deslieron_,
the vowels seem to be considered as forming separate syllables, the _i_
being treated as part of the stem and not of the suffix.
(d) The substantival ending _-ión_ (_acción_, etc.) is generally a
diphthong, and rarely suffers dissolution.
(e) In derivatives analogy operates: e.g., _naviero_ and _brioso_ with
their _i_ in a separate syllable because of _navío_ and _brío_ (cf. rule
4); but _glor[ie]ta_ and _ambic[io]so_ with a diphthong because of
_glor[ia]_ and _ambic[ió]n_. Ordinarily, such _ie_ and _io_ combinations
permit of synæresis if they are properly dissyllabic, and if properly
diphthongal they remain indissoluble. Still, adjectives in _-i.oso_ and
_-u.oso_ sometimes dissolve their diphthong; e.g., as in Espronceda:
El majestüoso río
Sus claras ondas enluta,
Garcilaso:
El árbol de victoria
Que ciñe estrechamente
Tu glorïosa frente.
(6) Two contiguous weak vowels with the accent on the first of them form
an indissoluble diphthong; e.g., _muy_. _Cuita_, _cuido_ and related
forms once accented the _u_: cf. p. 134, l. 20 where Cervantes has
_descuido_ in assonance with _confuso_. So also, Meléndez Valdés
assonated _tumba_ and _cuidan_. _Viùda_ was formerly _víuda_, and Tirso
de Molina assonated it with _Lucía_, _pican_, etc.
(7) If the second of two contiguous weak vowels is accented, there is a
diphthong sometimes indissoluble and sometimes dissoluble; e.g.,
indissoluble are _f[uí]_ and, in modern usage, _c[ui]ta_, _c[ui]do_ and
their derivatives; dissoluble are _ruin_, _ruina_, _ruido_, _viudo_.
These later, however, readily admit synæresis.
Analogy operates in verb forms; thus _u_ is in a syllable apart in
_huyo_, _arguyo_, and so also in _huimos_, _argüimos_ (but in such cases
synæresis is always possible). In cases of a repetition of the same
vowel, synæresis hardly obtains; therefore _piísimo_ and _duúnviro_ have
four syllables each.