I learned to speak Mandarin a while ago and have understanding of Kanji thanks to that. However, I'm new to learning and im tripping up over this, till i wrap my mind around it. Do Kanji have several pronunciations? for example. 日本. here it is "nippon", however, and when i see the second kanji in 六本木, it seems to be pronounced the same. However, in another example like 今日 the first is pronounced "kon" here while in a sentence like 今何時ですか it is pronounced as "ima".
My question is: Are these instances consistent at all? Perhaps when 今 is on its own its usually "ima" but when paired with other kanji it is pronounced differently? Or is it inconsistent and you can find sometimes it is still pronounced as "ima" even when paried with other kanji? also, when two kanji are paired, can the pronunciation of the word take a new form different from how they are both separately pronounced on their own?