Let's see the sentence you wrote. "I need to talk to you", which means "당신에게 해야할(need) 말(talk)이 있어요." In this case, the verb is translated in order as you suggested. Besides the verb "talk" looks like a noun after translating. Meanwhile, "I have a lot to do", which means " 할(do) 일이 많이 있어요(have)", the order of verb is reversed. The firs sentence is exceptional. Generally, the order of verb in Korean is in reversed compared to English. :)