yeohaeng gal ttae jageun binuwa syampureul gabange neoheoyo.

Literally, 여행 갈 때 means at the time of going on a trip.

• 여행 = travel, trip
• 가다 = to go
• 때 = time, when

So this phrase is commonly understood as when I go on a trip, when going on a trip, or when leaving for a trip, depending on context.

Before 때, Korean normally uses a verb in a modifying form.

• 가다 → 갈
• 갈 때 = when going / when one goes

So 가다 때 is not grammatical, and 가는 때 is not the normal form for this everyday pattern. In sentences like this, -(으)ㄹ 때 is the usual way to say when doing something.

Because 여행 가다 is a common Korean expression meaning to go on a trip.

Here, 여행 is not being treated like a direct object of 가다, so you do not normally add 을/를. A native speaker would usually say:

• 여행 가다 = to go on a trip
• 여행하다 = to travel

But 여행을 가다 sounds unnatural in standard everyday Korean.

Because 작다 is a descriptive verb/adjective meaning to be small, and before a noun it changes like this:

• 작다 → 작은

So:

• 작은 비누 = small soap

With descriptive verbs in Korean, you usually use -(으)ㄴ before a noun, not -는. That is why 작는 비누 is incorrect.

Most directly, 작은 modifies only 비누.

So the most literal reading is:

• small soap and shampoo

In context, a listener might guess that the shampoo is also travel-size, but grammatically 작은 is attached most clearly to 비누.

If you want to make it clear that both are small, you could say:

• 작은 비누와 작은 샴푸를 가방에 넣어요.

Because 와 connects the two nouns, and 를 marks the whole noun phrase as the object of the verb.

• 비누와 샴푸 = soap and shampoo
• 비누와 샴푸를 = soap and shampoo + object marker

The verb is 넣어요 (put in), and the thing being put in is small soap and shampoo, so the object marker appears on the last noun in the connected phrase.

와 and 과 both mean and, but the choice depends on the sound at the end of the noun before it.

• after a vowel: 와
• after a consonant: 과

Since 비누 ends in a vowel sound, you use 와:

• 비누와

Because 넣다 usually follows this pattern:

• A를 B에 넣다
• put A into B

So in this sentence:

• 작은 비누와 샴푸를 = the thing being put in
• 가방에 = into the bag

Here, 에 marks the destination/location that something goes into. The bag is not the direct object; the soap and shampoo are.

The subject is omitted because Korean often leaves out subjects when they are obvious from context.

So this sentence can naturally mean:

• I put a small soap and shampoo in my bag when I go on a trip
• We put...
• You put...

In many learning materials, it is often understood as I unless context says otherwise. If you wanted to make it explicit, you could say:

• 저는 여행 갈 때 작은 비누와 샴푸를 가방에 넣어요.

Korean present-tense forms often express habitual actions, not just something happening right now.

So 넣어요 here most likely means:

• I put
• I usually put
• I put it when I go on trips

It sounds like a general habit or routine. Korean does this very often.

They are similar, but the nuance is different.

• 여행 갈 때 = when going on a trip, often around the time of leaving or preparing to leave
• 여행할 때 = when traveling, during the trip in a broader sense

In this sentence, since it talks about putting things in a bag, 여행 갈 때 makes good sense because it sounds like preparation before departure.

Korean does not have articles like English a, an, and the.

So nouns like 비누, 샴푸, and 가방 do not need separate words for that. Whether they mean a bag, the bag, or my bag depends on context.

In this sentence:

• 작은 비누 could mean a small soap or small soap
• 가방에 could mean in a bag, in the bag, or in my bag

The exact English choice comes from the situation, not from a separate Korean article word.