di più is the comparitive form of 'much'
much | molto | adverb
more | più, di più | comparative
the most | (il) più | relative superlative
very much | moltissimo | absolute superlative
From: Italian Verbs and Essentials of Grammar, Carlo Graziano, 1987, p. 147
'Certain adverbs have irregular comparative, relative superlative, and absolute superlative forms.'
BTW - bene, male, and poco are also listed
well | bene | adverb
better | meglio | comparative
the best | (il) meglio | relative superlative
very well | ottimamente | absolute superlative
I thought the word reference for più was also was interesting to peruse, it shows a lot of other words used with it.
Nah, it's usually like Parlarare = Speak and TALK. It's like this Dire - Say, to tell (so it stands alone in first case "Lei ha detto che ..." She said that (in second," Lei mi ha detto che " - She told me that
& Raccontare - To tell, recount, relay qualcosa Ex. lui mi ha gia raccontato - he already told me Lui ha raccontato la historia? did he tell the story? L'ha raccontata = he told it.
In the situation above, I think dire would work best. Raccontare I think only works when there has been something said already and someone is simply passing it along.
Couldn't this sentence mean that there are certain days where I speak more than I should? I'm sure you guys are tired of people comparing Italian with Spanish but in this case I can't help it so here I go: in Spanish there's a difference between "ciertos días hablo más"="certain days I speak more" (than other days) and "ciertos días hablo DE más"="certain days I speak more than I should". Maybe the same happens in Italian?
I didn't try it because I tend to go literal with DL, but to me the best translation of this is 'some days I speak more'. 'Certo' can mean 'some'. If you use 'certain' it would be usual to say 'on certain days I speak more', but leaving out the 'on' is not wrong. Basically the two sentences ( some and certain) mean the same thing but there might be reasons when one usage is preferred over the other i.e. I speak more under certain conditions like 'fewer people in the room'/' I feel I have something to contribute' etc.