Diário is an ADJECTIVE and diariamente is an ADVERB. So, something that happens diariamente is something diário. Example: I watch this TV program diariamente because this program is diário. diariamente = happening everyday (daily) semanalmente = happening every week (weekly) mensalmente = happening every month (monthly) anualmente = happening every year. This suffix MENTE corresponds to LY in English. Examples: happily=felizmente; quickly=rapidamente. They are adverbs. Diário is an adjective. This newspaper is diário. This newspapel is semanal. This nespaper is mensal. A nespaper that is semanal is sold semanalmente. A newspaper that is mensal is sold mensalmente. Hope you got it. Cheers from Brasil

DIARIAMENTE- (it's an adverb) - TOMO DIARIAMENTE O MEU PEQUENO ALMOÇO (I have my breakfast daily) DIÁRIO - (it's a substantive) - Daily paper/daily event/log-book/Diary/journal/daily paper/ day-book

diariamente is an adverb and means every day. eu tomo banho diariamente. (I take a bath every day) eu estudo diariamente. (I study every day) diário is an adjective and means daily notícias diárias (daily news) correio diário (daily mail) You should use each being aware of the usage of adverbs and adjectives (adverbs aren't necessary for the general understanding of a phrase; they are just accessories) ex: Eu estudo. (that can be understood just by itself right?) ex: Eu estudo diariamente. (now, we call diariamente a temporal adverb wich indicates when or for how long the action is done.) (adjectives give attributes, qualities to a noun.) ex. Ele se exercita. (here, exercita is a verb.) ex. Ele pratica exercícios diários. (Now, it is a noun with the attribute "daily") there's also the noun Diário, wich means diary (nikki) or a daily newspaper diariamente and diário mean the same thing, you just need to be careful about the grammar in order to use them correctly.