How do Korean particles show the roles of nouns in a sentence?

In the Korean language, nouns attach specific particles to indicate their grammatical roles within a sentence. These case markers help clarify the relationship between nouns and the predicate.1

Key markers include:

• Subject: Marked by -i after a consonant or -ga after a vowel.1
• Direct Object: Marked by -ŭl after a consonant or -lŭl after a vowel.1
• Indirect Object: Typically marked by (h)ant’e or the less casual ege.1

These markers are not always mandatory; they are frequently omitted or replaced by focus particles. For example, particles such as -do or -to ("also," "even") are used to highlight a word, while -ŭn (after a consonant) or -nŭn (after a vowel) are used to background a topic.1