The Kanji for “Big” is 大 - Readings are たい and だい
However…they have an example for the word “Big” - 大きい
So I assumed this would be pronounced - ta-i-ki-i
however the reading of the vocab word “Big” is actually
So the question i guess is - why did the reading for the Big kanji become おお for the word ‘Big’? What’s the point in learning the kanji pronunciations if they change inside of a word? Why is there a ‘vocabulary word’ and a Kanji that are both for ‘Big’?
I just learned hiragana and katana and so far this has been my first major point of confusion.