Learn Hardcore Chinese: tā láidào zhè gè chéngshì yǐjīng sān nián le.

The verb 来到 (“to come (and arrive)”) refers to his original coming.
The pattern 来到这个城市已经三年了 means “three years have passed since that coming, up to now.”

In everyday communication, Chinese speakers use this sentence both to say when he came (three years ago) and that he has been here for three years and is still here now (unless context says otherwise).

What does the 了 at the very end do here?

The sentence‑final 了 (了 at the very end) shows a new situation / change of state and often has the sense of “by now / as of now.”

In patterns with a duration, like:

他来到这个城市已经三年了。
我在这家公司工作五年了。
他结婚十年了。

the final 了 signals that up to this moment, the situation has reached that length of time.

So here, 三年了 = “(it’s) three years now.”

Without that final 了, the sentence:

他来到这个城市已经三年。

sounds incomplete or at best much less natural in standard modern Mandarin. The 了 is strongly expected with this “up till now” meaning.

Why do we need both 已经 and 了? Aren’t they both like “already”?

They are related but not the same:

已经 (yǐjīng) explicitly means “already”.
Sentence‑final 了 marks a new current state / change and, with a duration, also implies “already reached (that amount of time).”

In 他来到这个城市已经三年了:

已经 adds explicit emphasis: “already.”
了 marks that the new state “three years have passed” holds now.

Compare:

他来到这个城市三年了。
– “He came to this city three years ago / He has been in this city for three years (now).”
(No 已经, still natural.)
他来到这个城市已经三年了。
– Same basic meaning, but 已经 makes the “already” feel a bit stronger or more highlighted.

So they often co‑occur, but you can drop 已经 without breaking the grammar. Dropping 了 is usually not OK here.

Can I move 已经 to another place in the sentence?

Yes, but you have to be careful about what sounds natural.

Your original sentence:

他来到这个城市已经三年了。
(Very natural; 已经 sits before the duration 三年.)

Other possibilities:

他来这个城市已经三年了。
- Dropping 到 is fine (see next question), structure is the same.
- Very natural.
他已经在这个城市三年了。
- Also very natural.
- Focus is more on “being in this city” than on the original act of “coming.”
他已经来到这个城市三年了。
- Grammatically understandable, but many speakers feel it’s a bit awkward, because 来到 is a “one‑moment” action (arrival), and we don’t usually think of “already arrived for three years.”
- In this order, it’s more idiomatic to switch 来到 to 在 or 住:
  - 他已经在这个城市三年了。
  - 他已经住在这个城市三年了。
他来到这个城市三年了已经。
- This is not normal word order. Putting 已经 at the very end sounds unnatural in regular speech/writing.

So, the safest and most natural versions:

他来到这个城市已经三年了。
他来这个城市已经三年了。
他在这个城市已经三年了。

Why do we need both 这 and 个 before 城市? Why not just 这城市?

Chinese almost always needs a measure word (classifier) between:

a number or demonstrative (一, 两, 这, 那, etc.)
and a countable noun.

So the normal pattern is:

这 + 个
- 城市 → 这个城市 (“this city”)

个 (gè) is the most common general classifier.

Can you say 这城市?

It exists, but it’s marked style: more literary, poetic, or headline‑ish.
In everyday modern Mandarin, learners should stick to:
- 这个城市 (this city)
- 那个城市 (that city)
- 三个城市 (three cities)

So yes, 个 is required in standard, neutral speech.

What’s the difference between 来到 and 来 here? Can I just say 来?

来 (lái) = “to come (toward the speaker or a reference point).”
到 (dào) = “to arrive at / to reach (a place).”
来到 (láidào) combines them and emphasizes arriving at a specific place.

In your sentence:

他来到这个城市已经三年了。
Emphasizes the event “coming (and arriving) in this city” as the starting point.

You can also say:

他来这个城市已经三年了。
– Very natural, especially in speech.

Difference in nuance:

来到 → a bit more formal / written, slightly stronger “arrival” feel.
来 → more colloquial, lighter.

In meaning, both here are fine: “It’s already been three years since he came to this city.”

Could we say 他在这个城市已经三年了 instead? What’s the difference?

Yes, that’s completely correct and very common:

他在这个城市已经三年了。

Subtle difference in focus:

他来到这个城市已经三年了。
- Viewpoint: the event of coming to the city.
- Literally: “It’s already been three years since he came to this city.”
他在这个城市已经三年了。
- Viewpoint: the state of being in the city.
- Literally: “He has already been in this city for three years.”

In practice, both usually imply: he came three years ago and is still there now.
If you mainly want to say “has been (staying) in this city”, the version with 在 is a bit more straightforward for learners:

他在这个城市三年了。
他在这个城市已经三年了。

How would I say clearly “He has lived in this city for three years”?

Use the verb 住 (zhù, to live / reside):

Most natural patterns:

他在这个城市住了三年了。
- Very typical spoken Chinese.
- “He has lived in this city for three years (and is still living here).”
他在这个城市已经住了三年了。
- Same meaning, with explicit “already.”

Structure:

Subject: 他
Location: 在这个城市
Verb: 住
Aspect: 了
Duration: 三年
Sentence‑final 了: marks “up to now”

If you say:

他在这个城市住了三年。

without the final 了, it usually means “He lived in this city for three years (but not anymore).”

So for “has lived and still lives there now,” keep the final 了:

在这个城市住了三年了。

Where is the English “has” in this Chinese sentence? How does Chinese show that tense?

Chinese doesn’t have verb tenses like English (no separate “has / have / had” forms).

Instead, it uses:

Aspect particles: like 了, 过, 着
Time expressions: 昨天, 现在, 明天, 三年, 已经, etc.

In 他来到这个城市已经三年了:

There is no direct word for “has.”
The combination of:
- the verb 来到 (came),
- the duration 三年,
- 已经 (“already”),
- and final 了 (current state),
gives the meaning “has been” / “has (now) spent three years here since coming.”

So “has” is not a separate word; it is expressed implicitly through the pattern and particles, especially the final 了 and the duration.

Why is there no word like “for” before “three years”? How do you say “for three years” in Chinese?

In Chinese, durations usually appear as a bare time phrase after the verb (or verb + object), without a preposition like “for.”

Examples:

我等了你三个小时。
– I waited (for) you for three hours.
他工作了五年。
– He worked for five years.
我学中文两年了。
– I have been learning Chinese for two years.

So in your sentence:

他来到这个城市已经三年了。

the 三年 by itself functions as “for three years” / “(it’s been) three years.”
There is no “for” word in Chinese in this use; the grammar handles it by position, not by a preposition.

Can I use 过 here, like 他来过这个城市三年了?

No, 过 (guò) doesn’t work in this pattern.

过 is the experiential aspect marker: it means someone has ever done something at least once in their life / experience, without focusing on duration or completion up to now.

他来过这个城市。
– He has been to this city before (at least once).
– No information about when or for how long.

But when you say 三年了, you are talking about a length of time:

how long it has been since he came,
or how long he has been here.

That meaning is expressed using 了, not 过:

✅ 他来到这个城市已经三年了。
✅ 他来这个城市已经三年了。
✅ 他在这个城市住了三年了。

So: 来过 … 三年了 is ungrammatical; 过 and a specific duration like 三年了 do not combine this way.

Why is 年 used here and not 岁? What’s the difference?

Both relate to “years,” but they’re used differently:

年 (nián)
- A general word for a year as a time period.
- Used for “three years” of work, study, living, etc.
- Examples:
  - 三年 (three years)
  - 五年以后 (after five years)
  - 他在北京住了三年。 (He lived in Beijing for three years.)
岁 (suì)
- A classifier for age (“years old”).
- Only used with people’s or animals’ age:
  - 他三岁。 (He is three years old.)
  - 我二十五岁。 (I’m 25 years old.)

In your sentence, 三年 describes a period of time since he came, not his age, so 年 is the correct word:

他来到这个城市已经三年了。 ✅
他来到这个城市已经三岁了。 ❌ (nonsense: “three years old since he came”)

So: 年 = years of duration/time, 岁 = years of age.