soni geonjohal ttaeneun rosyeoneul jogeum bareumyeon johayo.

손이 uses the subject marker 이, because 손 is the thing being described as dry.

• 손이 건조하다 = the hands are dry
• Here, 건조하다 describes the condition of the hands, so 손 is the grammatical subject.

If you said 손은, it would sound more like you were setting up hands as a topic, possibly with contrast, such as As for the hands, they’re dry.

In this sentence, 손이 is the most natural choice.

건조할 때 means when [the hands] are dry.

Then 는 is added to 때:

• 건조할 때 = when they are dry
• 건조할 때는 = when they are dry, as for that situation / in that case

This 는 gives a slight sense of topic or contrast. It often appears in advice sentences like this:

• 아플 때는 쉬세요. = When you’re sick, rest.
• 추울 때는 따뜻하게 입으세요. = When it’s cold, dress warmly.

So here, 때는 helps frame the sentence as general advice for that situation.

This is a very common learner question.

With 때 meaning when, Korean usually uses the form -(으)ㄹ 때 with descriptive verbs like this:

• 아프다 → 아플 때 = when it hurts / when someone is sick
• 바쁘다 → 바쁠 때 = when someone is busy
• 건조하다 → 건조할 때 = when it is dry

So 건조할 때 is the normal pattern.

Even though learners often know 건조한 손 = dry hands, that adjective form is not what is usually used before 때. With 때, the standard form is 건조할 때.

It literally breaks down like this:

• 로션을 = lotion
• 조금 = a little / a small amount
• 바르면 = if you apply / when you apply

So the phrase means:

if you apply a little lotion
or more naturally, applying a little lotion

In the full sentence, it gives advice: when your hands are dry, applying a little lotion is good.

-(으)면 is a very common ending meaning if or when.

• 바르다 = to apply
• 바르면 = if you apply / when you apply

In this sentence, it does not sound like a strong logical condition in English. It often has a softer, practical feeling:

• 이렇게 하면 좋아요. = It’s good to do it this way.
• 약을 먹으면 나아요. = If you take medicine, you’ll get better.

So 로션을 조금 바르면 좋아요 means something like:

• It’s good to apply a little lotion
• You should apply a little lotion
• Applying a little lotion helps

조금 means a little or a small amount, and here it modifies the action of applying lotion.

So:

• 로션을 조금 바르다 = to apply a little lotion

It refers to the amount of lotion used.

Korean often places words like 조금, 많이, 잘, 빨리 before the verb:

• 물을 많이 마셔요. = Drink a lot of water.
• 천천히 걸어요. = Walk slowly.
• 로션을 조금 바르세요. = Apply a little lotion.

바르다 means to apply, especially something like:

• lotion
• cream
• sunscreen
• makeup
• ointment

So it is the natural verb for putting something onto the skin.

Examples:

• 선크림을 바르다 = to apply sunscreen
• 크림을 바르다 = to apply cream
• 약을 바르다 = to apply medicine/ointment

English speakers sometimes want to translate it as put on or rub on, but apply is usually the cleanest meaning here.

Yes, literally 좋아요 means it is good, but in sentences like this it often means:

• it’s a good idea
• it helps
• you should
• it’s good to do that

So 로션을 조금 바르면 좋아요 does not just mean it is good in a vague way. It functions as soft advice.

Compared with stronger expressions:

• 바르세요 = Apply it. / Please apply it.
• 바르는 게 좋아요 = It’s good to apply it.
• 바르면 좋아요 = If you apply it, that’s good / It helps

This sentence sounds gentle and natural.

Yes, in a practical sense.

Korean often leaves out subjects and possessives when they are obvious from context. So although the sentence does not say you, the meaning is understood as something like:

• When your hands are dry, it’s good to apply a little lotion.

The sentence could theoretically describe people in general, not only one specific person, and that is actually part of why it sounds natural. It works as general advice.

Korean often omits possessives like my, your, and his/her when they are clear from context.

So:

• 손이 건조할 때는 naturally means when your hands are dry in a context where someone is being given advice.
• Korean does not need to say 당신의 손 or 네 손 unless there is some special reason to emphasize ownership.

In fact, saying your too often in Korean can sound unnatural.

Yes, 손이 건조하면 로션을 조금 바르면 좋아요 is possible, but it feels a little different.

• 건조할 때는 = when your hands are dry; in that situation
• 건조하면 = if your hands are dry

The difference is small, but:

• -할 때는 often sounds more like talking about a recurring situation or circumstance
• -하면 sounds more conditional: if that happens

For everyday advice, 건조할 때는 sounds very natural.

In Korean, 손 can mean hand or hands, depending on context.

So even though the word is singular in form, 손이 건조할 때는 can naturally be understood as:

• when your hand is dry
• when your hands are dry

In real-life contexts like lotion and skin care, many learners will understand it as hands in a general sense.

If someone wanted to be more explicitly plural, they might say 손이 건조할 때 anyway, because Korean often does not mark plural unless needed.

The sentence can be divided into two main parts:

1. 손이 건조할 때는
   = when the hands are dry / when your hands are dry

2. 로션을 조금 바르면 좋아요
   = it’s good to apply a little lotion

So the full structure is:

[In the situation when hands are dry], [applying a little lotion is good].

This is a very common Korean advice pattern:

• 피곤할 때는 일찍 자면 좋아요.
  = When you’re tired, it’s good to sleep early.

• 목이 아플 때는 따뜻한 물을 마시면 좋아요.
  = When your throat hurts, it’s good to drink warm water.

Once you recognize that pattern, this sentence becomes much easier to understand.