Long & Short Syllables
The intrinsic nature of the vowels in words, whether long or short, has be learned, or consulted in a dictionary showing this feature: it is not indicated by the spelling. Additionally, the rules in reading Latin verse are:
1. Vowels intrinsically long remain long.
2. Diphthongs are long.
3. A vowel followed by another vowel and not forming a diphthong is generally short (provided the word is not a Greek borrowing).
4. A short vowel ending a word or followed by single consonant (includes qu, ch, ph and th, but not x) stays short.
5. A short vowel followed by two or more consonants in same word (or single x) becomes long.
6. A short vowel followed by final single consonant in the word, and by another consonant starting the word following, becomes long.
7. Explosive consonants (cpt, gbd) or f are counted as belonging to the next syllable when followed by r or l. This can make the preceding vowel short, or at the poet’s wish, leave the vowel long, though the accent shifts to the following syllable.