A heavy syllable is dwelt on longer in pronunciation than a light
syllable.
For quantity, h does not count as a consonant, qu
counts as only one consonant, x (=ks) and z (=sd) each
count as two consonants, and “mute-liquid” combinations (b,c,d,f,g,p
or t PLUS l or r) sometimes are counted as only one consonant. So
patres (nom. pl. of pater) COULD be “scanned” (metrically
analyzed) as a word whose syllable-pattern is “light-heavy” (pa-tres)
OR “heavy-heavy” (pat-res), since its first vowel is short
by nature. (Note that with matres, for example, where the
a is long by nature, there is only one scansion possible:
heavy-heavy, no matter how the syllables are divided.)
ELISION: A syllable ending in a vowel or in –m is either
not pronounced or nasalized if it comes at the end of a word, before
a word starting with a vowel: prid(em) oportebat, noct(e)
egeris. If the 2nd word is est, then the e
in est is the one not pronounced, rather than the vowel or
-m syllable: magnum (e)st, magna (e)st. If the vowel
or syllable ending in -m is long by nature, it usually will not be
elided (so for instance in Demosthenem the final syllable will
always be pronounced, even if it comes before a vowel. For the most
part, a long vowel at the end of a word coming before a vowel at the
beginning of the next word is elided; but in the case of o,
u and i, it sometimes happens that the result is like
the addition of a consonant, v or j: immo age
for instance sounds like “im-mwa-ge.” See Allen’s Vox Latina
for more details.
STRESS (ACCENT): The weight of a syllable does not directly
affect its STRESS accent (sometimes called simply “accent”). The
Latin stress accent refers to the one syllable in a word that is regularly
pronounced more forcefully, and sometimes with higher voice-pitch.
One word may have two or more heavy syllables, but it will only have
one principal stress accent. Rules for where to stress a word: never
on the last syllable; if a word has more than 2 syllables, stress
it on the 3rd syllable from the end (antepenult) unless
the 2nd syllable from the end (penult) is heavy. If it
is, then stress it (the penult): TIN-ti-nant, te-GUN-tur.
Try pronouncing these words: ille, esse, deo, uidetur,
superare, diuos, sedens, aduersus, identidem, spectat, audit, dulce,
ridentem, misero, quod, omnis, eripit, sensus, mihi, simul, Lesbia,
aspexi, nihil, super, lingua, torpet, tenuis, artus, flamma, demanat,
sonitu, suopte, tintinant, aures, gemina, teguntur, lumina, nocte,
otium, Catulle, tibi, molestum est (2 words), otio exsultas (2 words),
nimiumque, gestis, otium et (2 words), reges, prius, beatas, perdidit
urbes (2 words).