eopdeiteureul hamyeon i aebi deo ppallajyeoyo.

Because 업데이트 is functioning as the object of 하다.

In Korean, many borrowed words and noun-like action words combine with 하다 to mean to do X. So:

• 업데이트 = update
• 업데이트를 하다 = to do an update / to update

The particle 를 marks 업데이트 as the thing being done.

So 업데이트를 하면 literally means if/when (someone) does an update.

This is very common in Korean. Many actions are expressed as:

• noun + 하다

especially with:

• loanwords
• Sino-Korean nouns
• formal action words

Examples:

• 공부하다 = to study
• 운동하다 = to exercise
• 업데이트하다 = to update

So 업데이트를 하다 and 업데이트하다 are both possible.

In real usage, people often shorten:

• 업데이트를 하면 → 업데이트하면

Both mean the same thing.

-면 means if or when, depending on context.

Here:

• 하다 = to do
• 하면 = if one does / when one does

So 업데이트를 하면 can mean:

• if you update (it)
• when you update (it)

In this kind of sentence, it usually gives a general result:

• If you update it, this app gets faster or
• When you update it, this app gets faster

Korean often leaves this kind of distinction to context.

Korean often omits subjects when they are obvious from context.

So 업데이트를 하면 does not explicitly say:

• I update it
• you update it
• we update it

It just says if/when (someone) updates it.

In a real situation, the listener usually understands who it is. In an app message, the natural interpretation is often:

• if you update it

This kind of subject omission is extremely common in Korean.

Because 이 앱 is the subject of 빨라져요.

The app is the thing that becomes faster.

So:

• 이 앱이 = this app (subject)
• 빨라져요 = becomes fast / gets faster

It is not the object of an action here. Nothing is being done to the app grammatically in this clause; rather, the app itself is changing state.

That is why 이/가 is used, not 을/를.

Both can be possible in different contexts, but 이/가 is natural here because it highlights the subject that is changing.

• 이 앱이 더 빨라져요 = This app gets faster.
• 이 앱은 더 빨라져요 would sound more like As for this app, it gets faster or contrast it with something else.

Using 이/가 often feels more direct and neutral when presenting a result or new information.

So in this sentence, 이 앱이 is a very natural choice.

더 means more.

So:

• 더 빨라져요 = becomes faster / gets more fast

In natural English, we say gets faster.

더 shows comparison, even if the comparison point is not stated explicitly. The implied meaning is:

• faster than before
• faster than it is now

This is an important grammar point.

• 빠르다 = to be fast
• 빨라요 = it is fast
• 빨라지다 = to become fast
• 빨라져요 = it becomes fast / gets faster

The sentence is talking about a change after updating, not just describing the app’s general quality.

So:

• 이 앱이 빨라요 = This app is fast.
• 이 앱이 더 빨라져요 = This app gets faster.

The -아/어지다 pattern often means to become ...:

• 좋아지다 = to become good / get better
• 커지다 = to become big / get bigger
• 느려지다 = to become slow / get slower

It comes from 빠르다.

Step by step:

1. 빠르다 = to be fast
2. Irregular stem change: 빠르- → 빨라- before a vowel ending
3. Add 지다 = to become
   
   • 빨라지다 = to become fast
4. Present polite form:
   • 빨라져요

Why 져요?

• 지어요 contracts to 져요

So:

• 빨라지어요 → 빨라져요

This is a very common contraction in Korean.

Technically, 빨라지다 means to become fast, but in many contexts the most natural English translation is to get faster.

Here, because the sentence also has 더, the meaning is clearly:

• gets faster
• becomes faster

So while the literal pieces are closer to become fast, the natural meaning in this sentence is definitely become faster.

Yes. Very often, the object particle 를 is dropped in casual or everyday speech, especially with expressions like this.

So both are possible:

• 업데이트를 하면
• 업데이트하면

The version with 를 is a little fuller and more explicit.
The version without it is very common in conversation and informal writing.

Both mean the same thing here.

빨라져요 is in the polite informal style, often called -요 style.

It is:

• polite
• natural in everyday speech
• common in app messages, customer communication, and general conversation

Related forms:

• 빨라집니다 = more formal
• 빨라져 = casual/intimate

So this sentence is polite and natural for a general user-facing message.

Grammatically, Korean leaves that open unless the context makes it specific.

• 업데이트를 하면 = if/when an update is done

In practice, with an app message, it usually means:

• if you update the app

But depending on context, it could also be understood more generally as:

• after updating
• once updated
• when the app is updated

Korean often relies on context instead of spelling out every role explicitly.

A close breakdown is:

• 업데이트를 = an update + object marker
• 하면 = if/when (someone) does
• 이 앱이 = this app + subject marker
• 더 = more
• 빨라져요 = becomes fast / gets faster

So very literally:

If one does an update, this app becomes more fast.

Natural English:

• If you update it, this app gets faster.
• Updating it makes this app faster.