There are several ways to say "I like tea". 1. 나는 차를 좋아해요. "나는" would be optional if it is pretty clear in context. "를" is added because "좋아하다" is a transitive verb. (We don't know whether the speaker likes other drinks or not) 2. 차는 좋아해요. (the speaker likes other drinks as well including "차") 3. 차가 좋아요.(compared to other drinks ) (We know the speaker prefers to drink "차" rather than coffee, soda, something like that.) \^o^/

I'm not an expert so I don't know if I will explain it right, but you should write : 나는 차를 좋아해요 -는 marks the subject who does the action of the verb : I like, "I" is the subject -를 marks the direct object of the verb : I like what ? Tea. 좋아해요 : the action of liking something