Here is the Korean dictionary definition of "이제야" : 말하고 있는 이때에 이르러서야 비로소. Here's my translation for it : finally to come to the moment at which one speaks, or does something. "이제야" is an adverb, which means "at last", "finally", or "eventually." You can interchange "이제야" with "이제서야", for they both mean the same. As you can see, in this context, "이제야" suggests that the one with you was silent, saying nothing, for long enough to make you bored or tired and that "at last" said something. In this case, you can say to him or her, "이제야 말하네요." But, a word of caution, you should be careful when you say it because it sometimes can offend others, depending on your tone. "~하네" means the same as "~하다." And you can mostly use it when you are "actually" talking with someone. Think of it as a colloquial way of saying "~하다." And as you know, you say "~요" to be polite. I hope this helps.