halmeonineun yesnare i dosie jaju gasseo.

는 marks 할머니 as the topic: as for grandmother...

So 할머니는 옛날에 이 도시에 자주 갔어 feels like:

• As for grandmother, she often went to this city in the old days.

If you used 할머니가, it would put more focus on who did the action, as if answering a question like:

• Who often went to this city?
  → 할머니가.

In many ordinary statements, 는 sounds more natural when you are talking about someone as the topic of the sentence.

옛날에 means in the old days, a long time ago, or back then.

It gives a broad past-time setting, not a specific date. It often has a nostalgic or old-time feeling.

Examples of the nuance:

• 옛날에 = long ago / in earlier times
• 예전에 = before / previously / in the past

So 옛날에 can sound a little more like back in the old days, while 예전에 is often more neutral.

In 옛날에, the 에 marks a time expression.

Korean often uses 에 with nouns that indicate a point or period of time:

• 월요일에 = on Monday
• 여름에 = in summer
• 옛날에 = in the old days

With some time words, 에 is optional, but 옛날에 is a very common fixed form.

Here, 에 marks the destination of movement with the verb 가다 (to go).

So:

• 이 도시 = this city
• 이 도시에 = to this city

With movement verbs, Korean commonly uses 에 for the place you go to:

• 학교에 가다 = go to school
• 집에 가다 = go home
• 도시에 가다 = go to a city

So 이 도시에 자주 갔어 means (she) often went to this city.

자주 means often.

In Korean, adverbs like 자주 usually come before the verb, so 자주 갔어 = often went.

This placement is very natural:

• 할머니는 옛날에 이 도시에 자주 갔어.

You may also see slightly different word orders depending on emphasis, such as:

• 할머니는 옛날에 자주 이 도시에 갔어.

That is still understandable, but the original order sounds very natural.

갔어 is casual/informal speech.

It is used with:

• close friends
• younger people
• children
• family members
• diary-style narration
• casual storytelling

The polite version would be:

• 갔어요

So the sentence in polite speech would be:

• 할머니는 옛날에 이 도시에 자주 갔어요.

The verb stem of 가다 is 가-.

Past tense is formed with -았/었-, and 가다 takes -았-, giving:

• 가 + 았어 → 갔어

So:

• 가다 = to go
• 갔어 = went

This is an irregular-looking spelling change, but it is a very common contraction pattern in Korean.

In this sentence, it can naturally be understood as used to go / would often go, because of the combination of:

• 옛날에 = in the old days
• 자주 = often
• past tense 갔어

So even though 갔어 is literally past tense (went), the whole sentence suggests repeated past action:

• Grandmother often went to this city in the old days.
• Grandmother used to go to this city often.

Korean often relies on context and adverbs like 자주 to create this habitual past meaning.

In Korean, family terms are often used without explicitly saying my when the meaning is obvious from context.

So 할머니 can mean:

• my grandmother
• grandmother
• sometimes an old woman, depending on context

In a sentence like this, learners often translate it as my grandmother, but Korean does not need to say 내 할머니 unless there is a reason to emphasize it or clarify it.

So Korean is often more context-dependent than English here.

Yes, depending on the situation, English may translate 가다 more naturally as go to, visit, or even come to in certain contexts.

Literally, 가다 means to go. But in good English, we sometimes say:

• She often went to this city
• She used to visit this city often

If the focus is on repeated trips to the city, visit can sound smoother in English, even though the Korean verb is still just 가다.

Usually, with 가다, the normal choice for a destination is 에:

• 도시에 갔어 = went to the city

로 is more like toward, by way of, or it can mark a direction or means in other contexts. With place nouns, 로 가다 can be used, but it often emphasizes direction or route more than simple destination.

For basic sentences like this, 도시에 갔어 is the standard and best choice.

Korean word order is more flexible than English, as long as the particles stay correct. The original sentence is very natural:

• 할머니는 옛날에 이 도시에 자주 갔어.

You could rearrange parts for emphasis, for example:

• 옛날에 할머니는 이 도시에 자주 갔어.
• 할머니는 이 도시에 옛날에 자주 갔어.

But not every rearrangement sounds equally natural. The original order is a smooth, standard way to say it:

1. topic: 할머니는
2. time: 옛날에
3. place: 이 도시에
4. frequency adverb: 자주
5. verb: 갔어

That pattern is very common in Korean.

Yes, 갔었어 is possible, but it is not exactly the same.

• 갔어 = went
• 갔었어 = had gone / used to go / went before

-었었- often adds a sense of:

• something further back in the past
• a past experience being recalled
• contrast with the present situation

So:

• 할머니는 옛날에 이 도시에 자주 갔어.
  = Grandma often went to this city in the old days.

• 할머니는 옛날에 이 도시에 자주 갔었어.
  = Grandma used to go to this city often back then.
  (slightly more reflective or contrastive)

In many situations, the simpler 갔어 is the more neutral choice.

Yes, 이 도시 is natural if the speaker wants to specify this city.

But Korean often omits words like this, that, or even the place entirely if the context already makes it clear.

So depending on context, people might also say:

• 할머니는 옛날에 자주 갔어.
  = Grandma used to go often.
• 할머니는 옛날에 그 도시에 자주 갔어.
  = Grandma often went to that city.

Including 이 is perfectly fine when the speaker is pointing out a particular city that is relevant to the conversation.