According to the accent rule (if im correct) for a noun with two syllables,
if the penult is long and the ultima is short, then the proper accent is circumflex on the penult.
For example, οἷκος since οι is long and κος is short, thus circumflex on iota.
Here is my question. Why is ὁ καιρός has an accent on the final syllable although the first syllable
is long but the final short?
Greek nouns are persistent which means they want a specific accent in a specific position but then the rules cut in that often mean that nouns have to take second best.
καιρός wants an accent on the ultima.
The rule is that a word is always permitted to have an accent on the ultima but it must be acute if the syllable is short and must have a circumflex if long.
As in the nominative καιρός has a short ultima it gets what it wants by having an acute.
In the genitive the ultima is long but it keep the same position by changing the accent to a circumflex - hence καιροῦ.
οἷκος by contrast wants a circumflex on the penult.
The rule for the penult is that it can always have an accent and this will be a circumflex i_f the penult is long and the ultima is short_ but an acute otherwise.
In the nominative it does have a long penult and a short ultima so it gets a circumflex but when in the genitive the ultima is long it changes its accent to an acute - hence οἴκου.
You will notice that the rules would allow both those nouns to avoid changing the accent by moving them. However nouns will always prefer to change an accent rather than move it.
The rules are not different for verbs but verbs differ in what they want. That is to say a verb will try and move its accent as far back as it can go.
According to the accent rule (if im correct) for a noun with two syllables, if the penult is long and the ultima is short, then the proper accent is circumflex on the penult.
Almost true, but not quite. Should read “any words accented on the penult, with long penult and short ultima, have the circumflex.”
λῦε. Κῦρος. But not καιρός, since it’s accented on the ultima. καῖρος, accented on the penult, is a different word (notice that it’s circumflex because of the rule) – it means “the row of thrums” in the LSJ. My wife, the weaver, tells me that thrums are the loose ends of thread that get cut off at the end of your project.
We’re way off topic now, but the fabulously lengthy Homer commentaries of Eustathius, 12th-cent. archbish of Thessalonica, consist mostly of material drawn from ancient commentaries as represented in the Homeric scholia. (We have his own autograph manuscript of his Iliad commentary, additions and all!)
The info re καῖρος comes from an ancient scholium on Od.7.107, καιροσέων δ’ οθονέων etc., a hapax.