(1) The acute (´) can stand only on one of the last three syllables of a word; the circumflex (῀) only on one of the last two; and the grave (`) only on the last.
Examples: This rule would be violated by ἄποστολος, for here the accent would stand on the fourth syllable from the end. It would also be violated by πιστεῦομεν, for here the circumflex would stand on the third syllable from the end.
(2) The circumflex accent cannot stand on a short syllable.
(3) If the ultima is long,
(a) the antepenult cannot be accented,
(b) the penult, if it is accented at all, must have the acute.
Rule( 3)(a) would be violated by ἀπόστολῳ, or ἀπόστολου, because in these cases the ultima is long; but it is not violated by ἀπόστολε or ἀπόστολοι, because here the ultima is short.
Rule (3)(b) would be violated by δοῦλου or δοῦλων, but is not violated by δοῦλος or δοῦλοι.
(4) If the ultima is short, a long penult, if it is accented at all, must have the circumflex.
Examples: This rule would be violated by δούλε or δούλοι; but it is not violated by δούλου, because here the ultima is not short, or by υἱός, because here, although a long penult comes before a short ultima, the penult is not accented at all. The rule does not say that a long penult before a short ultima must have the circumflex, but only that if it is accented at all it must have the circumflex rather than some other kind of accent.
(5) A long ultima can have either the acute or the circumflex.
Examples: ἀδελφοῦ and ἀδελφού both conform to the general rules of accent. Further observation, based on other considerations, is necessary in order to tell which is right.
(6) An acute accent on the last syllable of a word is changed to the grave when followed, without intervening mark of punctuation, by other words in a sentence.
Examples: ἀδελφός is right where ἀδελφός stands alone; but ἀδελφός ἀποστόλου violates the rule — it should be ἀδελφὸς ἀποστόλου.