In Korean, the object particles 을 and 를 are used to indicate the object of a sentence, much like how "to" or "the" might function in English. Their usage depends on whether the noun they follow has a final consonant (받침) or not. Here's a simple and detailed explanation for beginners:
1. What Are Object Particles?Object particles mark the object in a sentence — the person or thing that receives the action of the verb. For example:

• 사과를 먹어요 → "I eat an apple."
  • Here, 사과를 shows that "apple" is the object being eaten.

2. When to Use 을 or 를?The choice between 을 and 를 depends on the final sound of the noun:

• Use 을 if the noun ends with a consonant.
• Use 를 if the noun ends with a vowel.

3. Breaking It Down:(1) Use 을 after a consonantIf the noun ends with a consonant sound, attach 을:

• 책 (book) → 책을
  
  • 책을 읽어요. → "I read a book."
• 밥 (rice) → 밥을
  
  • 밥을 먹어요. → "I eat rice."

(2) Use 를 after a vowelIf the noun ends with a vowel sound, attach 를:

• 사과 (apple) → 사과를
  
  • 사과를 먹어요. → "I eat an apple."
• 영화 (movie) → 영화를
  
  • 영화를 봐요. → "I watch a movie."

4. Easy Rule for Beginners

• Check the last letter of the noun:
  1. If it has a 받침 (final consonant), use 을.
  2. If it doesn’t have a 받침 (ends in a vowel), use 를.

5. Quick PracticeHere are some nouns. Let’s add 을 or 를:

• 고양이 (cat) → 고양이를
• 물 (water) → 물을
• 커피 (coffee) → 커피를
• 책 (book) → 책을

6. Why This Matters?Using the correct object particle makes your sentence grammatically clear and helps you sound more natural in Korean.

7. Helpful TipThink of 을 and 를 as tools to connect the object to the action. This concept is unique to Korean grammar, but with practice, it will feel natural!