Проводник сказал, что чай будет позже, потому что вагон ещё не готов.

Here проводник means the train attendant / carriage attendant on a long-distance train, not an electrical conductor and not a tourist guide.

Russian проводник can mean different things depending on context:

• guide in some contexts
• conductor in physics/electricity
• train attendant on a train

Because the sentence mentions чай and вагон, the train meaning is the natural one here.

Сказал is the perfective past tense of сказать, and it means he said it as a completed act.

• сказал = he said / he told
• говорил = he was saying / he used to say / he spoke

In this sentence, the speaker is reporting one finished statement, so сказал fits best.

Что here means that and introduces reported speech:

• Проводник сказал, что...
• The attendant said that...

In English, that is often optional:

• He said (that) tea would come later

In Russian, что is normally used in this structure.

This is a very common question. Russian does not follow English-style sequence of tenses in the same way.

English often shifts:

• He said tea would be later

Russian usually keeps the tense that matches the actual situation from the speaker’s point of view:

• сказал, что чай будет позже = literally said that tea will be later

Even though English translates this as would be, Russian normally uses the future будет here.

Because чай is the subject of будет.

The structure is:

• чай будет позже = tea will be later

So:

• чай = nominative singular, the thing being talked about
• будет = future of быть
• позже = later

If чай were a direct object, you might expect another case, but here it is the subject.

Позже means later.

Yes, it is historically a comparative form, similar to:

• поздний = late
• поздно = late
• позже = later

Russian often uses comparative forms as adverbs in very natural ways:

• раньше = earlier
• быстрее = faster
• позже = later

So чай будет позже literally means tea will be later.

Because потому что is the full conjunction meaning because.

• потому что = because
• потому by itself usually means for that reason / therefore / because of that, and it works differently

Examples:

• Я ушёл, потому что устал. = I left because I was tired.
• Я устал, потому и ушёл. = I was tired, and that’s why I left.

In your sentence, a full subordinate clause follows, so потому что is the normal choice.

Here ещё means yet / still.

So:

• ещё не готов = not ready yet / still not ready

This is a very common Russian pattern:

• ещё не знаю = I don’t know yet / I still don’t know
• ещё не пришёл = he hasn’t arrived yet

The exact English translation depends on context, but yet is a very natural choice here.

Because готов is the short form of the adjective, and Russian often uses the short form in predicate position, especially for states.

• вагон ещё не готов = the carriage is not ready yet

Compare:

• готовый = full adjective form, more like ready as a descriptive quality
• готов = short form, often used after to be in the sense of a current state

This is very common:

• Он готов. = He is ready.
• Она готова. = She is ready.
• Они готовы. = They are ready.

Вагон means railway car / carriage / coach.

In train context, it refers to one car of the train, not the whole train. Depending on the situation, English might translate it as:

• carriage
• coach
• railcar
• car

Here it probably means the train car is not yet prepared for serving tea or for passengers in some way.

Yes, Russian word order is flexible, but this version is the most neutral.

Neutral structure:

• Проводник сказал, что чай будет позже, потому что вагон ещё не готов.

You could change the order for emphasis, for example:

• Чай будет позже, сказал проводник...
  This emphasizes tea will be later.
• Потому что вагон ещё не готов, проводник сказал, что чай будет позже.
  This foregrounds the reason.

Russian word order often shows focus and emphasis, not just grammar.

Russian has no articles like a and the.

So:

• проводник can mean a conductor/attendant or the conductor/attendant
• чай can mean tea or the tea
• вагон can mean a carriage or the carriage

Russian relies on context instead. In this sentence, English naturally uses the because the speaker and listener probably know which attendant, tea, and carriage are meant.

Yes, it is natural, especially in context. It means something like:

• Tea will come later
• Tea will be served later
• The tea will be later

Russian often leaves some things implicit when the context is obvious. In a train setting, чай будет позже naturally suggests that the tea service will happen later, even though words like подадут or принесут are not stated.

So the sentence is short, normal, and idiomatic.