Лучше не спорить сразу, а сначала переспросить, если что-то непонятно.

Yes, Russian often leaves those words unstated.

Лучше + infinitive is a very common way to give general advice:

• Лучше подождать. = It’s better to wait.
• Лучше не спорить. = It’s better not to argue.

So Лучше не спорить сразу, а сначала переспросить... means something like It’s better not to argue right away, but first ask again...

You could make it more explicit:

• Вам лучше не спорить... = You’d better not argue...
• Лучше вам не спорить... = It’s better for you not to argue...

But in the original sentence, the advice is general, so no person is named.

Because after лучше, Russian often uses infinitives to talk about actions in a general way.

This structure is similar to English:

• Better not to argue
• Better to ask again first

So:

• лучше не спорить = better not to argue
• лучше ... переспросить = better ... to ask again

The sentence is not tied to a specific subject like я, ты, or мы. It is giving general advice about what one should do.

Both а and но can mean but, but they are not used in exactly the same way.

Here а is more natural because it sets up a contrast between two alternatives:

• не спорить сразу, а сначала переспросить
• not argue right away, but instead first ask again

This is a very typical Russian pattern:

• не X, а Y = not X, but Y

So а here means something like but rather / but instead.

If you used но, it would sound less like a clean contrast between two options and more like a simple but. Russian strongly prefers не X, а Y in this kind of sentence.

They are both about time, but they mean different things:

• сразу = immediately, right away
• сначала = first, at first, before anything else

So in this sentence:

• не спорить сразу = not argue right away
• а сначала переспросить = but first ask again

The contrast is very natural:

• don’t react immediately
• first clarify

So сразу focuses on immediacy, while сначала focuses on sequence.

Переспросить means to ask again, to ask for repetition, or to ask again for clarification.

It is built from:

• спросить = to ask
• переспросить = to ask again / ask back / ask for clarification

In this sentence, it suggests something like:

• asking the speaker to repeat
• checking whether you understood correctly
• clarifying something before starting an argument

So it is not just any question. It specifically means ask again because something may not be clear.

This is a very useful aspect contrast.

• спорить is imperfective
• переспросить is perfective

Why?

1. не спорить

Here the idea is don’t get into arguing / don’t engage in argument.
The imperfective works well for a general activity, especially after negation:

• лучше не спорить = it’s better not to argue

It refers to the action as a type of behavior, not as one completed event.

2. сначала переспросить

Here the idea is do one clear action first: ask again / clarify.
That is why the perfective is natural:

• переспросить = ask again once, as a complete step

So the sentence contrasts:

• avoiding the activity of arguing
• doing one concrete clarifying action first

It means if something is unclear.

A few things are happening here:

1. No present-tense to be

Russian normally does not use есть in the present tense here.

So:

• что-то непонятно literally = something unclear
• natural English = something is unclear

2. непонятно is a predicate

Here непонятно means unclear / not understandable in a predicative sense, like:

• понятно = clear / understandable
• непонятно = unclear

Compare:

• Мне всё понятно. = Everything is clear to me.
• Если что-то непонятно... = If something is unclear...

3. The person can be left unstated

Russian does not have to say to you if it is obvious from context.

So:

• если что-то непонятно = if something is unclear
• если вам что-то непонятно = if something is unclear to you

The version with вам is more explicit, but the original is perfectly natural.

Because непонятно here is not an adjective modifying a noun. It is being used as the predicate: is unclear.

Compare:

• что-то непонятно = something is unclear
• что-то непонятное = something unclear / some unclear thing

So:

• если что-то непонятно = if something is unclear
• если что-то непонятное by itself would sound incomplete, because it is just a noun phrase

In other words, непонятно describes the situation, while непонятное describes a thing.

Yes, but there is a small nuance.

• если что-то непонятно = if something is unclear
• если что-нибудь непонятно = if anything is unclear

Both are possible. The original with что-то is very natural and common.

A rough difference:

• что-то points to some unspecified thing
• что-нибудь can sound a bit more open-ended: anything at all

In many everyday situations, the difference is small, but если что-то непонятно is probably the most standard choice here.

There are two commas for two different reasons.

1. Before а

• Лучше не спорить сразу, а сначала переспросить...

This comma separates the contrast не X, а Y:

• not argue right away,
• but instead first ask again

2. Before если

• ..., если что-то непонятно

This comma introduces a subordinate clause:

• если что-то непонятно = if something is unclear

So the punctuation reflects the structure:

• main advice
• contrasted alternative
• conditional clause

Yes, Russian word order is flexible, but the original order is very natural.

Original:

• Лучше не спорить сразу, а сначала переспросить, если что-то непонятно.

Why it works well:

• сразу comes after спорить and naturally modifies the idea argue right away
• сначала comes before переспросить and emphasizes first ask again

You could rearrange words, but the emphasis would shift. For example:

• Лучше сразу не спорить... puts more emphasis on right away
• Лучше сначала переспросить, а не спорить сразу... foregrounds the clarifying action even more

So yes, the order can change, but the original is smooth, neutral, and idiomatic.