bibimbabeun meokgi jeone jal bibyeoya haeyo.

은 is the topic marker. It marks 비빔밥 as the thing being talked about: as for bibimbap...

So the sentence has a feeling like:

• As for bibimbap, you have to mix it well before eating.

It is not exactly the same as an English subject marker. In Korean, the topic marker often sets the general topic or gives contrast.

For example, 비빔밥은 can sound like:

• When it comes to bibimbap...
• Bibimbap, on the other hand...

depending on context.

-기 전에 means before doing ...

It is made from:

• 먹다 = to eat
• 먹기 = eating / the act of eating
• 전에 = before

So:

• 먹기 전에 = before eating

The -기 turns the verb into a noun-like form, so literally it is something like before eating or before the act of eating.

You will see this pattern a lot:

• 자기 전에 = before sleeping
• 가기 전에 = before going
• 공부하기 전에 = before studying

Yes. 먹기 전 and 먹기 전에 are both used.

• 먹기 전 = before eating
• 먹기 전에 = before eating

In many everyday sentences, they are very similar.
The version with 에 often feels a little more complete or standard in a full sentence, but both are natural.

So you may hear:

• 먹기 전에 잘 비벼야 해요.
• 먹기 전 잘 비벼야 해요.

Both work.

Here 잘 means well, but in this sentence it is closer to thoroughly or properly than skillfully.

So 잘 비벼야 해요 means:

• You have to mix it well
• You should mix it thoroughly

It does not mean you need some special talent at mixing bibimbap. It just means the mixing should be done properly.

This is a very common use of 잘 in Korean.

비벼야 해요 comes from the grammar pattern:

• -아/어야 해요 = have to / must / should

So:

• 비비다 = to mix
• 비벼야 해요 = have to mix / should mix

In this sentence, it expresses necessity:

• You have to mix it well before eating.

Depending on context, -아/어야 해요 can sound like:

• strong necessity: must
• normal instruction: have to
• practical advice: should

Here it feels like a normal instruction or recommendation.

This is because of how -어야 attaches to the verb stem.

• dictionary form: 비비다
• verb stem: 비비-
• • -어야
• result: 비비어야
• contracted form: 비벼야

So 비비어야 becomes 비벼야, which is the natural spoken and written form.

This kind of contraction is very common in Korean.

A similar example:

• 마시다 → 마셔야 해요
• underlying idea: 마시어야 해요 → 마셔야 해요

Because the grammar pattern is -아/어야 하다.

The 하다 part carries the meaning of it is necessary to do.
So even though the main action is 비비다 (to mix), the full structure is:

• 비벼야 하다 = it is necessary to mix
• 비벼야 해요 = polite present form

So the sentence is not using 하다 as the main lexical verb meaning to do by itself. It is part of the necessity expression.

Yes. 비벼야 돼요 is very common and means almost the same thing.

• 비벼야 해요
• 비벼야 돼요

Both mean:

• You have to mix it
• You should mix it

Very roughly:

• -아/어야 해요 can sound a little more neutral or textbook-like
• -아/어야 돼요 is extremely common in conversation

In everyday speech, both are natural.

The sentence ends in -해요, so it is in the polite informal style, often called the 해요 style.

• 비빔밥은 먹기 전에 잘 비벼야 해요. = polite
• 비빔밥은 먹기 전에 잘 비벼야 해. = casual
• 비빔밥은 먹기 전에 잘 비벼야 합니다. = more formal

So the original sentence is appropriate for everyday polite speech, such as talking to a customer, a classmate you are being polite to, or someone you do not speak casually with.

Because 비빔밥 has already been introduced as the topic with 은, and the object is understood from context.

So Korean does not need to repeat it as an object. The meaning is naturally understood as:

• As for bibimbap, before eating, you have to mix it well.

If you wanted, Korean could be more explicit in some contexts, but the original sentence is completely natural as it is.

This kind of omission is very common in Korean when the meaning is already clear.

No. Korean often leaves out the subject when it is obvious from context.

So the sentence does not literally say you. But in natural English, we translate it with you because that is what the sentence means in context:

• You have to mix bibimbap well before eating.

Depending on context, it could also mean:

• One should mix bibimbap well before eating.
• People should mix bibimbap well before eating.

Korean often relies on context instead of stating the subject directly.