1. Scansion of Latin Poetry
(How classical rhythm works)

2. Overview
Latin, like may other classical languages, uses quantitative meter for its verse. This means that unlike English, where the accent of a given syllable determines its value in verse, a Latin syllable's value is determined by the length of time it takes to say it.

3. ELLISION
If two words are on the same poetic line, and the first ends with a vowel or m, and the second begins with a vowel or h, the last syllable of the first word and the first syllable of the second word elide, forming a single consonant, which has the value of the longer of the two syllables.
This syllable is pronounced either as a combination of the two syllables, or, by individual choice, as the second syllable. If the second word is est, "is," the syllable is pronounced as the first syllable with "-st" added to the end.

4. LONG BY NATURE:
A vowel that is long, i.e. marked with a macron makes its syllable long. It is then called "long by nature.“
Since most scansion activities do not have macrons, this often must be checked using a dictionary.

5. æ, au, ei, eu, oe, and ui, DIPTHONGS
This also includes the diphthongs:
æ, au, ei, eu, oe, and ui,
but only when none of the vowels in the dipthongs are long or marked by a dieresis (e.g. diêî or âëreus.)

6. LONG BY POSITION
If a vowel has two or more consonants between itself and the next vowel, it makes its syllable "long by position."
The letter x (and sometimes z) counts as two consonants for the purposes of scansion.
The digraphs (two-letter combinations) ch, ph, th, qu and sometimes gu and su count as single consonants.
A mute (b,c,d,g,p, or t) followed by a liquid (l or r) can count as a single consonant, as long as they are in the same word.