sikdangeseo menyupaneul bogo mwo meogeulji jeonghaeyo.

에서 marks the place where an action happens. In this sentence, the actions 보고 and 정해요 happen at the restaurant, so 식당에서 means at the restaurant.

Compare:

• 식당에 가요 = go to the restaurant
• 식당에서 먹어요 = eat at the restaurant

So here, 식당에서 is correct because the sentence is describing what someone does in that location.

을/를 marks the direct object of a verb. Here, 메뉴판을 보고 means look at the menu.

The verb is 보다 = to see/look at, and the thing being looked at is 메뉴판, so it takes the object marker 을.

• 메뉴판을 보다 = to look at the menu

Because 메뉴판 ends in a consonant, it uses 을 rather than 를.

보고 is the -고 form of 보다. The -고 ending connects verbs and often means and or after doing something.

So:

• 메뉴판을 보고 = look at the menu, and...
• then 뭐 먹을지 정해요 = decide what to eat

In this sentence, 보고 shows that the first action leads into the next one:

look at the menu and decide what to eat

It does not necessarily mean a long time passes between the two actions. It just links them naturally.

뭐 먹을지 means what to eat or more literally what one will eat in the sense of a choice being decided.

This pattern is very common:

• verb stem + -(으)ㄹ지 = whether / which / what / where / how to do something

Here:

• 먹다 → 먹을지
• 뭐 먹을지 = what to eat / what they should eat / what they’re going to eat

It is used before verbs like:

• 정하다 = decide
• 고민하다 = think over
• 모르다 = not know

Examples:

• 뭐 먹을지 몰라요. = I don’t know what to eat.
• 어디 갈지 정해요. = We decide where to go.

That is a very common question. Both forms can appear in Korean, but they are used differently.

• 먹을지 points to a future choice or undecided action: what to eat
• 먹는지 usually means whether someone is eating or whether someone eats, often in an indirect question about an ongoing or general fact

So in this sentence, the speaker is deciding on a future action, so 먹을지 is the natural form.

Compare:

• 뭐 먹을지 정해요. = decide what to eat
• 그 사람이 지금 밥을 먹는지 몰라요. = I don’t know whether that person is eating now

뭐 is the casual spoken form of 무엇, and it is extremely common in everyday Korean.

So:

• 뭐 먹을지 = natural and conversational
• 무엇을 먹을지 = more formal or written

In ordinary speech, native speakers usually say 뭐. Since the sentence ends in the polite -요 style, using 뭐 still sounds perfectly normal.

Korean often leaves out the subject when it is obvious from context. That is very natural.

So 식당에서 메뉴판을 보고 뭐 먹을지 정해요 could mean:

• I look at the menu and decide what to eat
• we look at the menu and decide what to eat
• people do this in general

The subject does not need to be stated unless it matters.

If you wanted to include it, you could say:

• 저는 식당에서 메뉴판을 보고 뭐 먹을지 정해요.
• 우리는 식당에서 메뉴판을 보고 뭐 먹을지 정해요.

But leaving it out is often more natural.

정해요 is the 해요-style polite form. It is polite and neutral, and it is one of the most commonly used speech levels in Korean conversation.

The verb is 정하다 = to decide.

Conjugation:

• 정하다
• 정해요

Other related forms:

• 정해 = casual, plain spoken style
• 정합니다 = more formal and official
• 정했어요 = decided
• 정할 거예요 = will decide

So this sentence sounds polite and natural for everyday use.

It can mean either, depending on context.

In Korean, the present tense often covers both:

1. a general/habitual action

   • At restaurants, we look at the menu and decide what to eat.

2. an action happening in the current situation

   • We’re at the restaurant, looking at the menu and deciding what to eat.

Without more context, both are possible. Korean often relies on situation and context more than English does.

Yes, 결정하다 could also work, but 정하다 is usually the more natural everyday choice here.

• 정하다 = decide, choose, settle on
• 결정하다 = decide, make a decision, often a little more formal or weighty

For choosing food from a menu, 정하다 sounds very natural:

• 뭐 먹을지 정해요.

You could say:

• 뭐 먹을지 결정해요.

but it may sound a bit more formal or slightly heavier than necessary for a simple menu choice.

Grammatically, you can build similar expressions with -는 것, but in this case 뭐 먹을지 정해요 is much more natural.

Why?

• -(으)ㄹ지 정하다 is a standard pattern for deciding what/whether/how to do
• 먹을 것을 정하다 sounds more like choose the thing to eat, which is possible, but not the most natural way to phrase this exact idea

More natural alternatives include:

• 뭐 먹을지 정해요.
• 먹을 메뉴를 정해요. = decide which menu item to eat / choose what to order

So the original sentence is a very typical and useful pattern to remember.

Yes, Korean word order is flexible, especially when particles make the roles clear. But some orders sound more natural than others.

Original:

• 식당에서 메뉴판을 보고 뭐 먹을지 정해요.

Possible variation:

• 메뉴판을 보고 식당에서 뭐 먹을지 정해요.

However, the original order sounds smoother because 식당에서 sets the scene first, and then the actions follow.

Also, the final verb should stay at the end of the sentence, because Korean is basically a verb-final language.

It can suggest both, depending on how you understand the flow.

• At the simplest level, -고 links actions: look at the menu and decide
• In context, it often naturally implies sequence: after looking at the menu, decide

So 보고 does not strongly mark time the way -고 나서 does, but it often carries a natural sense that one action comes before the next.

Compare:

• 메뉴판을 보고 정해요. = look at the menu and decide
• 메뉴판을 보고 나서 정해요. = decide after looking at the menu

The second one makes the sequence more explicit. The original is more natural for everyday speech.

Yes, if the location is already understood from context.

Then you could simply say:

• 메뉴판을 보고 뭐 먹을지 정해요.

That would still sound completely natural. Korean often omits information that the listener can already guess.

The full sentence includes 식당에서 only to make the setting clear.