gwaireun naengjanggo-e neoheo dumyeon orae gayo.

If you keep fruit in the refrigerator, it lasts a long time.

Breakdown of gwaireun naengjanggo-e neoheo dumyeon orae gayo.

• ~에: destination particle
• ~은: topic particle
• 과일: fruit
• 넣어 두다: to keep (by putting in and leaving)
• ~면: if/when
• 냉장고: fridge
• 오래: for a long time / a long time
• 가다: to last / to go

Questions & Answers about gwaireun naengjanggo-e neoheo dumyeon orae gayo.

Why is it 과일은 and not 과일이/과일을?

과일은 uses the topic marker -은/는 to talk about fruit in general and set it up as the topic: As for fruit…
If you used 과일이, it would feel more like emphasizing fruit as the grammatical subject (often contrastive or in contexts like “Fruit (not something else) lasts long…”).
과일을 would mark fruit as the direct object, which would fit better in a sentence focusing on the action put fruit (into the fridge) rather than making a general statement about its shelf life.

What does 냉장고에 mean here, and why -에?

냉장고에 means in/into the refrigerator.
The particle -에 marks a destination/location. With movement verbs like 넣다 (to put in), -에 naturally marks the place you put something into.

What’s the grammar of 넣어 두면?

It’s 넣어 두다 + -면:

• 넣다 = to put in
• -어/아 두다 = to do something and leave it that way (keep it in that state for later)
• -면 = if/when
  So 넣어 두면 is like if you put it in and leave it there (stored).

How is 넣어 두면 different from just 넣으면?

• 넣으면 = if you put it in (simple action)
• 넣어 두면 = if you put it in and keep it there / leave it stored
  In real life, 넣어 두면 fits the idea of storing fruit in the fridge, not just placing it there momentarily.

Does -면 mean “if” or “when” here?

In Korean, -면 can work as if or when, depending on context.
In a general truth/habit statement like this, it often feels like when/if you do it (in general): When you keep fruit in the fridge, it lasts longer.

Why does the sentence end with 가요? Doesn’t 가다 mean “to go”?

Yes, 가다 literally means to go, but 오래 가다 is a very common expression meaning to last (a long time) (about food, batteries, trends, relationships, etc.).
So 오래 가요 = it lasts a long time.

What does 오래 do in 오래 가요?

오래 is an adverb meaning for a long time / long.
It modifies 가요 (from 가다) to form the set meaning last long.

Why is the subject (like “it/they”) not explicitly stated?

Korean often omits subjects when they’re clear from context. Here, it’s understood that fruit is what lasts longer, so (과일은) already covers the topic, and you don’t need an explicit it/they.

Is 과일 singular or plural here?

It can be either. Korean nouns often don’t mark plural unless needed. In this sentence it’s a generic statement, so 과일 is best understood as fruit (in general).

What level of politeness is 가요?

가요 is the informal-polite style (해요체). It’s polite and very common in everyday conversation.
More formal would be 갑니다/가요-style statements like 오래 갑니다, but that sounds more formal/statement-like.

Can I also say 과일을 냉장고에 넣어 두면 오래 가요?

Yes. 과일을 makes fruit the direct object of 넣어 두면 (if you put fruit in the fridge and keep it there).

• 과일은 … 오래 가요 = topic/general fact about fruit
• 과일을 … 넣어 두면 … = more action-focused: If you store fruit in the fridge…

How do I pronounce 넣어 and why does it look tricky?

넣어 comes from 넣다 + -어. It’s pronounced roughly like neo-eo, often blending quickly in speech.
Also note: 넣다 has an irregular-looking spelling because the base ends with ㅎ-like behavior historically, but for learners it’s best to memorize 넣다 → 넣어 as a set.