Learn Hardcore Chinese: tā juéde zuò huǒchē lǚyóu hěn shūfu, zài huǒchē shàng yě kěyǐ kàn zhàopiàn. - He feels that traveling by train is very comfortable, and on the train you can also look at photos.

觉得 = to feel, to think (subjectively)
- 他觉得坐火车旅游很舒服。
  He feels / finds that traveling by train is very comfortable.
想 has two main uses:
1. to want: 我想喝咖啡。 – I want to drink coffee.
2. to think, to consider (often about plans/thoughts in your head): 我在想明天做什么。 – I’m thinking about what to do tomorrow.
Using 想 in the original sentence would sound more like “he is thinking about” rather than “he has the impression that”.
认为 = to believe, to hold the opinion that (more formal, logical, or reasoned)
- 他认为坐火车旅游很环保。 – He believes that traveling by train is very environmentally friendly.

So 觉得 is best because “finding something comfortable” is about subjective feeling, not planning (想) or a formal judgment (认为).

Why is 坐 (zuò) used with 火车 (huǒchē)? Does 坐火车 literally mean “sit the train”?

Yes, 坐 literally means to sit, but with vehicles it is the standard verb meaning to take / ride (a vehicle).

Common patterns:

坐车 – to take a car / bus (depending on context)
坐火车 – to take the train
坐飞机 – to fly / take a plane
坐船 – to take a boat

So 坐火车 is the normal way to say “go by train” or “take the train”. It doesn’t focus on the physical act of sitting; it’s just the default verb for using that kind of transport.

The phrase 坐火车旅游 has two verbs: 坐 and 旅游. How does that work, and why is the order like that?

In 坐火车旅游, the structure is:

坐火车 – to take the train / go by train (manner or means)
旅游 – to travel (for pleasure, to go on a trip)

So 坐火车旅游 literally means “to travel (旅游) by taking the train (坐火车)”.

This is a common pattern in Chinese:

坐飞机出差 – to go on a business trip by plane
骑自行车上班 – to go to work by bike
开车旅游 – to travel by car

You could say:

坐火车去旅游 – go (somewhere) to travel by train

…but 坐火车旅游 is more compact and focuses on the way you travel (by train) as part of the activity of traveling. The train is the means; 旅游 is the main activity.

Why do we need 很 (hěn) before 舒服 (shūfu)? Can we just say 他觉得坐火车旅游舒服?

In modern spoken Chinese, when an adjective is used as a predicate (like 舒服 = “comfortable”), it almost always takes a degree adverb such as:

很 – very / quite (often weak in meaning)
非常 – extremely
真 – really
挺 … 的 – quite …

So 他觉得坐火车旅游很舒服 is the natural pattern:
Subject + 觉得 + [clause with 很 + adjective]

If you say 他觉得坐火车旅游舒服, it:

is grammatically possible,
but sounds either:
- a bit stiff or unusual in everyday speech, or
- like a contrastive statement (e.g. “He thinks traveling by train is comfortable (but something else isn’t)”).

In basic learner grammar, it’s safe to remember:

When you say “X is Adj” about a state, you usually insert 很:
天气很冷, 他很高, 这里很安静.

Here 很 does not always mean “very” strongly; it often just makes the sentence sound natural.

In English we have comfortable (adjective) and comfortably (adverb). Is 舒服 (shūfu) an adjective or an adverb in this sentence?

In Chinese, many words don’t strictly separate “adjective” and “adverb” the way English does.

舒服 is mainly an adjective meaning “comfortable”. But Chinese doesn’t need to change its form to modify a verb:

这个椅子很舒服。 – This chair is very comfortable.
这样坐着很舒服。 – Sitting like this is very comfortable.

In your sentence:

坐火车旅游很舒服。

Literally: “Traveling by train is very comfortable.”
Chinese doesn’t need an adverb like “comfortably”; instead, it says the whole situation is comfortable. So 舒服 works like “is comfortable” rather than “comfortably”.

Why is it 在火车上 (zài huǒchē shàng) and not just 在火车? What does 上 (shàng) do here?

在…上 is a very common pattern to express “on / in / on board” for certain places and vehicles.

在火车上 – on the train (on board the train)
在飞机上 – on the plane
在车上 – in the car / on the bus
在路上 – on the road / on the way
在网上 – on the internet

Here, 上 does not literally mean “on top of” the train; it indicates the space of that vehicle or surface.

You can sometimes say 在火车里 (inside the train), but 在火车上 is much more idiomatic when you mean “while you are on the train (as a passenger)”.

Saying only 在火车 without 上 or 里 sounds incomplete and unnatural in this context.

Why is 他 (tā) not repeated in the second clause 在火车上也可以看照片?

Chinese often drops the subject when it’s clear from context. This is called subject omission or pro‑drop.

The full version could be:

他觉得坐火车旅游很舒服，(他)在火车上也可以看照片。

Repeating 他 is not necessary, because it is obviously the same person doing both actions.

This happens a lot in Chinese:

我很累，(我)想休息一下。
他们到了北京，(他们)马上去酒店。

As long as the subject does not change, leaving it out after the first mention is very natural.

What is the function of 也 (yě) here, and why is it placed before 可以?

也 means “also / too”. It marks that this action is another possibility or activity, in addition to something already mentioned.

Basic placement rule:

Subject + (time / place) + 也 + (auxiliary verb like 可以/能/会) + main verb

In your sentence:

(他) – (he) [omitted]
在火车上 – on the train
也 – also
可以 – can
看照片 – look at photos

So the clause means:
“On the train, he can also look at photos.”

Placing 也 before 可以 is standard: it modifies the whole possibility (can also do X), not just the verb 看 alone.

Could we say 也可以在火车上看照片 instead? Is that different from 在火车上也可以看照片?

Yes, 也可以在火车上看照片 is also grammatical and natural.
Both:

在火车上也可以看照片
也可以在火车上看照片

are acceptable.

Subtle nuance:

在火车上也可以看照片
- Slightly emphasizes the place: “On the train, you can also look at photos (among other things you can do there).”
也可以在火车上看照片
- Slightly emphasizes that this is another option: “You can also look at photos on the train (in addition to doing it elsewhere or doing other activities).”

In everyday conversation, most people won’t feel a strong difference; both are fine.
What you should avoid is something like 可以也在火车上看照片, which is ungrammatical because 也 generally cannot come after 可以 like that.

What is the difference between 可以 (kěyǐ) and 能 (néng)? Could we say 在火车上也能看照片?

Yes, 在火车上也能看照片 is possible, but there is a nuance.

可以 often expresses:
- permission: may / be allowed to
- possibility: it is possible
能 often expresses:
- ability: be able to (have the skill or capacity)
- circumstantial possibility: the situation allows it

In this sentence, the idea is:

On the train, it’s possible / allowed to look at photos as a comfortable activity.

So 可以 is slightly more natural:
在火车上也可以看照片。 – You can (are able/allowed to) look at photos on the train.

Using 能 puts a bit more focus on the practical possibility or ability (for example, because there is time, space, or a phone), but in many casual contexts 可以 and 能 overlap and are both acceptable.

In 看照片 (kàn zhàopiàn), why is there no measure word like 张 (zhāng)? When do we use 张照片?

照片 can be used:

Without a measure word when you talk about photos in general or as an activity:
- 我喜欢看照片。 – I like looking at photos.
- 在火车上也可以看照片。 – You can also look at photos on the train.
With a measure word when you specify number or one specific photo:
- 一张照片 – one photo
- 几张照片 – several photos
- 给我看那张照片。 – Show me that photo.

In your sentence, the focus is on the activity (looking at photos in general), not on counting them. So 看照片 without 张 is exactly right.

Does this sentence talk about the present, the past, or a general habit? How does Chinese show tense here?

Chinese does not mark tense the way English does (no verb endings like -ed, -s). Instead, it relies on:

context
time words (昨天, 现在, 常常, 明天, etc.)
aspect particles like 了, 过, 着

Your sentence:

他觉得坐火车旅游很舒服，在火车上也可以看照片。

By itself, this is most naturally understood as:

a general statement or habit:
“He (in general) finds traveling by train comfortable, and on the train he can also look at photos.”

If you want to make it clearly past, you can add time words:

以前他觉得坐火车旅游很舒服… – In the past he thought traveling by train was comfortable…
昨天他觉得坐火车旅游很舒服… – Yesterday he felt that traveling by train was very comfortable…

So the original sentence is tense‑neutral and typically read as a general opinion / habit.

I see 旅 (lǚ) and 游 (yóu) written separately in the breakdown. Is 旅游 (lǚyóu) one word or two? Do the two characters each have meaning?

In modern Chinese, 旅游 (lǚyóu) is treated as one word meaning to travel / tourism, usually for pleasure.

The characters individually:

旅 – travel, journey
游 – to roam, to travel, to wander, to play

Combined, 旅游 is a disyllabic verb (and also a noun: tourism). In dictionaries and everyday usage, it’s one lexical item, like “travel” or “tourism” in English.

The word-by-word breakdown you saw is just for learning purposes (pinyin per character). In actual grammar, think of 旅游 as a single verb or noun.

What is the difference between 旅游 (lǚyóu) and 旅行 (lǚxíng)? Could we say 坐火车旅行很舒服 instead?

Both 旅游 and 旅行 refer to travel, and they overlap a lot.

General tendencies:

旅游
- Often emphasizes tourism / sightseeing / leisure trips.
- Common in phrases like: 旅游景点 (tourist attraction), 旅游团 (tour group), 旅游城市 (tourist city).
旅行
- More general word for travel / journey / trip, not necessarily only for tourism.
- Common in 旅行社 (travel agency), 旅行计划 (travel plan).

In your sentence:

他觉得坐火车旅游很舒服。 – He thinks traveling (as tourism) by train is very comfortable.
他觉得坐火车旅行很舒服。 – Also acceptable; sounds very similar in meaning.

Most learners can treat them as near‑synonyms for “travel”, with 旅游 feeling a bit more like tourism and 旅行 a bit more like journey/trip.

Why is there a comma ， between the two parts instead of using something like 和 (hé) for “and”?

Chinese punctuation works differently from English.

Your sentence:

他觉得坐火车旅游很舒服，在火车上也可以看照片。

This comma separates two closely related clauses with the same subject:

He feels traveling by train is comfortable.
On the train, he can also look at photos.

The second clause gives an additional reason or explanation for why it’s comfortable.

In Chinese, you do not usually connect whole clauses with 和 (and) the way English connects sentences with “and”. 和 mainly connects nouns / noun phrases:

他和我 – he and I
苹果和香蕉 – apples and bananas

It is not typically used like:

✗ 他觉得坐火车旅游很舒服和在火车上也可以看照片。 (unnatural)

Instead, Chinese uses:

a comma (，)
or a linking word like 而且, 并且, 还, depending on nuance.

So the comma here is the normal, natural way to join two related clauses.