waipaiga kkeunhgimyeon sueop yeongsangi meomchwoyo.

와이파이 means Wi-Fi.

The -가 is a subject particle, so 와이파이가 means the Wi-Fi as the thing being talked about.

In this sentence, the Wi-Fi is the thing that gets disconnected, so -가 is natural.

• 와이파이가 끊기면 = if/when the Wi-Fi gets cut off
• 수업 영상이 멈춰요 = the class video stops

A learner might expect 와이파이는, but -는 would add more of a topic/contrast feeling, like:

• 와이파이는 끊기면 수업 영상이 멈춰요
  = As for Wi-Fi, if it goes out, the class video stops

That is possible in some contexts, but the original sentence with -가 is the most straightforward.

끊기면 comes from the verb 끊기다, which means things like:

• to be disconnected
• to be cut off
• to drop (as with a signal or connection)

Then -면 means if/when.

So:

• 끊기다 = to get disconnected
• 끊기면 = if/when it gets disconnected

In this sentence:

• 와이파이가 끊기면 = if the Wi-Fi gets disconnected

Good question. The difference is basically about what kind of verb is being used.

• 끊다 = to cut / to disconnect something
• 끊기다 = to be cut / to be disconnected

So:

• 누가 와이파이를 끊어요 = Someone disconnects the Wi-Fi
• 와이파이가 끊겨요 = The Wi-Fi gets disconnected

In your sentence, the Wi-Fi is not actively doing the cutting. It is the thing that ends up disconnected, so 끊기다 is the right choice.

That is why 와이파이가 끊기면 sounds natural:

• if the Wi-Fi gets disconnected

수업 means class, lesson, or instruction.
영상 means video.

Together, 수업 영상 means:

• class video
• lesson video
• lecture video

The exact English translation depends on context, but it usually refers to a video used for class or a recorded lesson.

Because in the second part of the sentence, the video is the thing that stops.

So the structure is:

• 와이파이가 끊기면 = if the Wi-Fi gets disconnected
• 수업 영상이 멈춰요 = the class video stops

Here, 영상이 is the subject of 멈춰요.

So the sentence has two clauses, and each clause has its own subject:

• 와이파이 → gets disconnected
• 수업 영상 → stops

That is why you see both 와이파이가 and 영상이.

멈춰요 comes from 멈추다, which means:

• to stop
• to come to a stop
• to freeze (depending on context, especially for videos or screens)

So in this sentence, 수업 영상이 멈춰요 means:

• the class video stops
• the lesson video freezes

In real-life context, if Wi-Fi cuts out, 멈춰요 often feels like freezes in English, even though the Korean verb literally means stops.

Korean often uses the present tense in statements about:

• general facts
• repeated situations
• predictable results

So 멈춰요 here does not only mean stops right now. It can also mean:

• stops
• will stop
• tends to stop

depending on context.

That is why:

• 와이파이가 끊기면 수업 영상이 멈춰요

can naturally mean:

• If the Wi-Fi cuts out, the class video stops
• If the Wi-Fi gets disconnected, the class video will stop

Korean does not always need a separate future form where English does.

It can mean if or when, depending on context.

The grammar -면 expresses a condition:

• if X happens, Y happens

But in many everyday sentences, especially where the result is expected, it can feel like when.

So this sentence could be understood as:

• If the Wi-Fi gets disconnected, the class video stops
• When the Wi-Fi gets disconnected, the class video stops

The difference is mostly in how certain the speaker thinks the event is, and English handles that distinction more explicitly than Korean sometimes does.

It most naturally sounds like a general rule or usual result.

It is like saying:

• Whenever the Wi-Fi cuts out, the class video stops
• If the Wi-Fi goes down, the lesson video freezes

Because it uses -면 and the plain polite present 멈춰요, it sounds like a normal consequence, not just a one-time event.

If you wanted to talk about one specific past incident, Korean would usually mark that more clearly.

The sentence structure is:

A면 B
= If/when A, B

In your sentence:

• 와이파이가 끊기면 = if the Wi-Fi gets disconnected
• 수업 영상이 멈춰요 = the class video stops

So the full pattern is:

• [condition] + [result]

This is a very common Korean structure.

Yes, Korean word order is more flexible than English, though some orders sound more natural than others.

The original sentence is the most natural neutral order:

• 와이파이가 끊기면 수업 영상이 멈춰요.

You could also say:

• 수업 영상이 와이파이가 끊기면 멈춰요.

This is still understandable, but it sounds less smooth in ordinary conversation because the condition clause is usually placed first.

So for learners, it is best to remember:

• condition first
• result second

멈춰요 is in the -아요/어요 polite style, which is the standard polite speech used in everyday Korean.

It is appropriate for:

• normal conversation
• explanations
• customer service
• class situations
• everyday written notices

A more formal version would be:

• 와이파이가 끊기면 수업 영상이 멈춥니다.

Both mean the same thing, but:

• 멈춰요 = polite, everyday
• 멈춥니다 = more formal, official, or presentation-like

A natural pronunciation is roughly:

• 와이파이가 끈키면 수업 영사이 멈춰요

A few sound changes happen:

• 끊기면 is often heard closer to 끈키면
• 영상이 links together and sounds like 영사이

You do not need to force these too much at first, but it helps to recognize them when listening.

A rough romanization would be:

• waipai-ga kkeun-gi-myeon sueop yeong-sang-i meom-chwo-yo

But listening to native audio is much more helpful than relying on romanization.