Here I have the rules for the stress from my schoolbooks. The stress is different in Latin and in Greek words, but he could be only on one of the last 3 syllables.
Definition:
last syllable - ultima
syllable before last - paenultima
3. syllable from behind - antepaenultima
Now it goes!
1. Stress in Latin words (easy I think):
a) In words with 2 syllables the stress is always on the paenultima.
e.g.
Roma, stress on 'o'
b) In words longer than 2 syllables the stress is on the paenultima if the
paenultima is long.
e.g. Romanus, stress on 'a'
If the paenultima is short then the stress is on the antepaenultima!
e.g. perfidus, stress on 'e'
Which
vowels are long, which are short you have to learn, sorry!
2. Stress in Greek words is not so easy, for there are 3 different accents, and the
duration of a syllable can be long or short by nature or by position, and there
are special rules for Composita and so on.
So I want to restrict me to the Latin stress only!
Regards,
Jochen