When we use English, we cannot use two verb in a clause. So we have to make a verb to 'to-v' or '-ing'. Like English, we can change the form of verb in Korean. For example, in this sentence 나는/ 영어 공부하기를(to study English) /원해. (I / want / to study English.), we have to make a verb 공부하다 to 공부하기. Actually, it's so difficult to explain, even though I'm a Korean. :) If you have more questions, please let me know. Have a nice day~

As you know, 'want' is ~하고 싶다. ~하기를 원하다. want (to something) -> something을 하고 싶다. something고 싶다. it's normally used with 'I' I want to choose you. -> 나는 너를 선택하고 싶다. 나는 너를 선택하길(기를) 원한다. You can use with the other one like 'you', 'he', 'she' and so on. But that time you have to consider more. Here are examples. She wants to choose me -> 그녀는 나를 선택하고 싶어한다. 그녀는 나를 선택하기를 원한다. not 그녀는 나를 선택하고 싶다. She wants me to choose -> 그녀는 내가 선택하기를 원한다. not 그녀는 내가 선택하고 싶다(or 싶어한다). It's complicated...lol