hi bert, milman parry showed that homer repeated words, instead of inventing new ones, wherever possible.
you'll particularly notice this in the 2nd half of lines: often homer uses formulas with stock epithets here, from the masculine, feminine caesura or the bucolic diaresis. when the wars kick off and people start dropping off (a few books into homer) you'll really notice the repetition.
also the "he said", "he replied" lines before/after dialogue are very formulaic. homer not only uses the same stock words for e.g. "he said", but puts these words in exactly the same position in the line every time
, and builds up the rest of the line by putting in a stock formula name after the word, and a stock formula before it as well.
milman parry notes a whole lot of these patterns in his phd and other papers
e.g. verbs ending -eto naturally sit just before the bucolic diaresis, so you get ...eto (short short) then a dactyl and a spondee (like dios [someone]) to end the line. such constructions often have a participle plus a conjunction or particle sitting in the first half of the line to round out the idea and fit the metre...
william harris also noted in one of his "read homer" essays that he started reading comfortably after a few hundred lines.
as a bit of trivia, milman parry also statistically compared homer's frequency of word repetition to apollodorus, virgil and others who wrote their books all by themselves (and not in a bardic tradition passed down to homer by previous epic poets)... the other writers use lots more metrically identical
synonyms, whereas homer very rarely uses synonyms which are metrically identical... that's why they say homer is much more "efficient" with his vocab.