the answer for ur example is "λΆν°"
I've been wanting to go to Korea since I was a university student.
λνμ λλΆν° νκ΅μ κ°κ³ μΆλ€. (I want to go to Korea since I was university student)
other example..
μ΄μ λΆν° λμ΄ λ§μ΄ μμ.
It snows a lot since yesterday.