naengjanggo-e issneun soseureul kkeonae juseyo.

It breaks down like this:

• 냉장고에 = in the refrigerator
• 있는 = that is / which is located
• 소스를 = sauce + object marker
• 꺼내 주세요 = please take out

So the overall structure is:

[냉장고에 있는] [소스를] [꺼내 주세요]

Literally, it is something like:

Please take out the sauce that is in the refrigerator.

The part 냉장고에 있는 works like an English relative clause describing 소스.

있는 comes from the verb 있다, which often means to exist, to be located, or to have depending on context.

Here, it means to be located:

• 냉장고에 있다 = to be in the refrigerator

When Korean uses a verb to describe a noun, it changes the verb into a noun-modifying form. So:

• 있다 → 있는
• 냉장고에 있는 소스 = the sauce that is in the refrigerator

So 있는 is not a full sentence verb here. It is a modifier attached to 소스.

Because 있다 normally uses 에 for location.

• 냉장고에 있다 = to be in the refrigerator

The particle 에서 is usually used for:

• the place where an action happens
• the place something comes from in some contexts

But 있다 is not an action like eat, study, or work. It describes existence or location, so 에 is the natural choice.

That is why 냉장고에 있는 소스 is correct.

Because 소스 is the direct object of 꺼내다.

• 꺼내다 = to take out

What are you taking out?
The sauce.

So Korean marks 소스 with the object particle -를:

• 소스를 꺼내다 = to take out the sauce

Since 소스 ends in a vowel sound, it takes -를 rather than -을.

꺼내다 means to take out, to get out, or to pull out.

In this sentence:

• 꺼내 = the -아/어 connective form of 꺼내다
• 주세요 = please give / please do

Together, 꺼내 주세요 means:

Please take it out.

This is a very common Korean request pattern:

• verb stem + 아/어 주세요

Examples:

• 문을 닫아 주세요 = Please close the door.
• 물 좀 주세요 = Please give me some water.
• 소스를 꺼내 주세요 = Please take out the sauce.

In Korean, -아/어 주세요 is a standard way to make a polite request.

It literally comes from the idea of do X and give it, but in modern Korean it simply functions as please do X.

So:

• 꺼내 주세요 = please take out
• 읽어 주세요 = please read
• 기다려 주세요 = please wait

This pattern is softer and more natural than just using a blunt imperative.

For learners, the safest standard form is 꺼내 주세요 with a space.

That is because 주다 here behaves like a separate auxiliary verb in the pattern -아/어 주다.

So:

• 꺼내 주세요 = standard spacing to learn and use

You may also see attached forms in casual writing, but 꺼내 주세요 is the best form to follow in careful standard writing.

Both can be translated as a polite command, but the nuance is a little different.

• 꺼내 주세요 = Please take it out.
• 꺼내세요 = Take it out, please. / Please take it out.

In many situations they are both natural, but -아/어 주세요 often sounds a bit warmer or more like a request for help, while -세요 can sound a bit more direct.

So 꺼내 주세요 is very common when asking someone to do something for you.

Yes, you could, and it is natural.

But the nuance is slightly different:

• 냉장고에 있는 소스를 꺼내 주세요 = Please take out the sauce that is in the refrigerator.
• 냉장고에서 소스를 꺼내 주세요 = Please take the sauce out of the refrigerator.

The original sentence uses 냉장고에 있는 to identify which sauce you mean.
The 에서 version focuses more directly on the refrigerator as the place you are taking it out from.

In many real situations, both sentences could work.

Korean usually does not use a separate relative pronoun like English that, which, or who.

Instead, Korean puts the descriptive clause directly in front of the noun:

• 냉장고에 있는 소스 = sauce that is in the refrigerator

So where English says:

• the sauce that is in the refrigerator

Korean says:

• refrigerator-in existing sauce

This is one of the most important sentence patterns in Korean: the modifier comes before the noun.

By itself, 소스 does not tell you whether it is singular or plural. Korean nouns often do not mark number unless it is necessary.

So 소스 could mean:

• sauce
• sauces

In this sentence, English would usually translate it as the sauce because the context suggests one specific sauce. But Korean itself does not force singular in the same way English does.

It is polite and appropriate for everyday situations.

The politeness comes from 주세요, which is a standard polite request form. It is suitable for:

• family members
• coworkers
• store staff
• people you are speaking politely to in daily life

It is not extremely formal, but it is definitely polite.
A casual version would be:

• 냉장고에 있는 소스 꺼내 줘

A more formal version could be:

• 냉장고에 있는 소스를 꺼내 주십시오

So the original sentence sits in the very common, useful middle level of politeness.