Teacher taught me to write "I like drama" as "나는 드라마를 좋아해요" but my Korean friend corrected and rewrote it as "나는 드라마가 좋아요". This sort of situation caused some confusion, especially when I was a beginner struggling to learn Korean as a foreign language.
But it is no big deal even if such 'confusion' is not resolved, so long as you can accept both sentences are of the same meaning. Koreans can understand what you mean when you say "드라마를 좋아해요", although they may find it awkward.
Such trivial omission will not be a stumbling block later and I know it because I never quite find the answer to my query before moving on to higher level learning. My query was, "How can action verb (좋아하다, means to like) and adjective (좋다, means good or fine) be the same?"
I think I have finally found my answer after many years.
Among the adjectives, there are some adjectives that are always directly link to the inner feeling and thinking of the people who use them. Adjective like 좋다, 싫다, 기쁘다, 슬프다 and 무섭다 describes the "me" in I. They can be called the "psychological adjectives" (심리형용사, 心理形容詞). For example,
나는 슬프다 (I am sad)
나는 기쁘다 (I am happy)
Such "psychological adjectives" must always take the first person perspective because it describes the speaker's personal feeling. For example,
나는 빌리의 승진이 매우 기쁘다.
"I am very happy about Billy's promotion." - This sentence uses 기쁘다 from the first person perspective, so it is correct.
너는 빌리의 승진이 매우 기쁘다.
"You are very happy about Billy's promotion." - This sentence uses 기쁘다 from the second person perspective and it is wrong.
그는 빌리의 승진이 매우 기쁘다.
"He is very happy about Billy's promotion". - This sentence uses 기쁘다 from the third person perspective, so it is also wrong.
나는 빌리의 승진이 매우 기뻤니?
"Was I happy about Billy's promotion?" - This sentence is wrong as it does not make sense since 기쁘다 is used to express my (the first person) feeling and not to question my own feeling.
너는 빌리의 승진이 매우 기뻤니?
"Were you happy about Billy's promotion?" - This sentence is correct because you are asking someone directly about his feeling. When the person responds, he is very likely to use 기쁘다 from the first person perspective as in "네, 나는 매우 기뻤어요." (Yes, I was very happy)
그는 빌리의 승진이 매우 기뻤니?
"Was he happy about Billy's promotion?" - This sentence is wrong because it is not asking for a first person's response.
In the situation when psychological adjective is changed to verb by adding "아/어 하다", it also 'loses' its "psychological" aspect. What this means is verb 기뻐하다, which is formed from adjective 기쁘다, is no longer restricted to the first person perspective; it is applicable to all perspectives. For example, the following six sentences are all grammatically correct.
나는 빌리의 승진을 매우 기뻐했다.
너는 빌리의 승진을 매우 기뻐했다.
그는 빌리의 승진을 매우 기뻐했다.
나는 빌리의 승진을 매우 기뻐했니?
너는 빌리의 승진을 매우 기뻐했니?
그는 빌리의 승진을 매우 기뻐했니?
At this point, I finally understood why my teacher would only teach me to use "좋아하다" and not "좋다", "싫어하다" and not "싫다", to express my likes and dislikes. I cannot be wrong in any circumstances if I use "좋아하다" but I can be wrong in some circumstances if I use "좋다". This is perhaps one of the many compromises that has to be introduced in order to make the Korean language easier to understand for foreigners.