Many Korean learners get confused between "μ/λ" and "μ΄/κ°."
The meaning slightly changes depending on whether you use "μ/λ" or "μ΄/κ°." I will now explain the major differences.
π μ΄/κ°: Emphasizing the subject
μ μΉκ΅¬κ° μ΄λμ μ’μν΄μ. My friend likes exercise.
(Emphasizing "My friend")
π μ/λ: Emphasizing something other than the subject
(when emphasizing the predicate)
μ μΉκ΅¬λ μ΄λμ μ’μν΄μ. My friend likes exercise.
(Emphasizing "like exercise")
π μ΄/κ°:
π Subject marker indicating the subject
π Positioned after new information to emphasize a specific noun or subject and convey new information
π Answer to "λκ° λΌλ©΄μ λ¨Ήμ΄μ?" (Who is eating ramen?) -> λλκ° λ¨Ήμ΄μ. (My sister is eating.)
π Used in double-subject sentences and embedded clauses
μΉκ΅¬λ μ΄ λ°μ§λ₯Ό μμ΄μ. My friend bought these pants.
+
μ΄ λ°μ§λ μλ»μ. These pants are pretty.
-> μ μΉκ΅¬κ° μ° λ°μ§λ μλ»μ.
The pants that my friend bought are pretty.
π Used with predicative markers 'λλ€' (to become) and 'μλλ€' (not to be)
μ λ μ μλμ΄ λμμ΅λλ€. I became a teacher.
κ·Έ μ¬λμ μΈκ΅μΈμ΄ μλμμ. That person is not a foreigner.
π μ/λ:
π Topic marker indicating the topic
π Used after the topic in a declarative sentence to convey general information
π Answer to "λλκ° λ¬΄μμ ν΄μ?" (What is your sister doing?) -> λλλ μ΄λν΄μ. (My sister exercises)
π Used to contrast
μ λ μ¬κ³Όλ₯Ό μ’μνμ§λ§ λΈκΈ°λ μ μ’μν΄μ.
I like apples, but I don't like strawberries.