siheomi kkeutnamyeon jibeseo joyonghi swil geoyeyo.

-이/가 marks the subject of the clause. Here, 시험이 끝나면 means when the exam ends (literally, if/when the exam ends).
If you used 시험은, it would feel more like as for the exam… / speaking of the exam…, adding a topic/contrast nuance.

-면 attaches to a verb to mean if/when. In this sentence, it sets a condition/time: When the exam ends, …
Other options are possible, with slightly different nuance:

• 시험이 끝나면: when/if it ends (common, neutral)
• 시험이 끝나고 (나서): after it ends (more clearly “after”)
• 시험이 끝난 후에: after the exam has ended (more formal/explicit)

-면 can mean both if and when, depending on context.

• If: when it’s a true condition/possibility
  Example: 비가 오면 안 갈 거예요. = If it rains, I won’t go.
• When: when it’s a likely/expected future event or a general timing setup
  Here, finishing the exam is expected, so 시험이 끝나면 is naturally when the exam ends.

• 집에 focuses on destination/where you go or where something exists:
  집에 갈 거예요. = I’ll go home.
  집에 있어요. = I’m at home.
• 집에서 focuses on the place where an action happens:
  집에서 쉴 거예요. = I’ll rest at home. (resting happens there)

Since 쉬다 is an action occurring in a location, 집에서 is the natural choice.

조용히 is an adverb meaning quietly. It describes how you will rest.
Adverbs in Korean usually come before the verb they modify, so 조용히 쉴 거예요 is the standard placement.

You could also move it for emphasis, but 집에서 조용히 쉴 거예요 is the most natural.

Future/intent modifier -(으)ㄹ attaches to the verb stem:

• 쉬다 → stem 쉬-
• Add -ㄹ (because the stem ends in a vowel): 쉬- + ㄹ = 쉴 So 쉴 거예요 = will rest / am going to rest.

-(으)ㄹ 거예요 expresses a future plan/prediction: will / going to.
-어요/아요 style is polite, everyday speech, appropriate for most situations.

More formal: 쉴 겁니다
More casual (to close friends): 쉴 거야

Sometimes, but the meaning changes.

• 쉴 거예요: neutral future plan/prediction (I’m going to rest / I will rest)
• 쉴게요: a promise/decision often made in response to someone, with a nuance of “Okay, I’ll rest (then)” or “I’ll do it” (often considering the listener)

If you’re just stating your plan, 쉴 거예요 fits best.

Korean often omits the subject when it’s clear from context. This sentence doesn’t explicitly say I, but it’s commonly understood as I will rest in context.

If you want to specify:

• 저는 시험이 끝나면 집에서 조용히 쉴 거예요. = As for me, when the exam ends, I’ll rest quietly at home.

Yes, a few common ones:

• 시험이 is pronounced [시허미] (the ㅁ moves to the next syllable before the vowel)
• 집에서 is pronounced [지베서] (the ㅂ moves to the next syllable)
• 끝나면 is pronounced [끈나면] (the final consonant affects the following ㄴ, making it sound like ㄴㄴ)