할 줄 알다 is not always "can do" - Korean Q&A
The meaning of the sentence "그 사람이 영어 할 줄 알았어요." can change depending on the intonation and the context. Hyunwoo explains how this happens by giving your various intonation examples. Free audio lesson on -줄 알다: https://talktomeinkorean.com/lessons/l6l27 Browse through our store and get your best Korean study material!: http://bit.ly/store-podcast