Лучше отложить этот разговор до завтра, если все уже устали.

No, nothing is missing. Лучше is very commonly used in Russian in an impersonal pattern:

• Лучше + infinitive
• Лучше сделать...
• Лучше подождать...
• Лучше отложить...

It means It is better to... or Better to...

So:

• Лучше отложить этот разговор до завтра
  = It’s better to postpone this conversation until tomorrow

Russian often leaves out words like это or будет when they are not necessary. Adding them would usually sound heavier or less natural here.

Because after лучше in this kind of sentence, Russian usually uses the infinitive to express a general recommendation or best course of action.

So the structure is:

• Лучше + infinitive

Examples:

• Лучше уйти сейчас. — Better to leave now.
• Лучше не спорить. — Better not to argue.
• Лучше отложить этот разговор. — Better to postpone this conversation.

This is similar to English better to do something.

This is about aspect.

• отложить = perfective
• откладывать = imperfective

Here, the sentence refers to one complete action: postponing the conversation to tomorrow. Because the focus is on a single, completed decision/action, Russian uses the perfective:

• Лучше отложить этот разговор до завтра.

If you used откладывать, it would sound more like a repeated or ongoing idea, which does not fit as well here.

So:

• отложить = postpone once / as a complete action
• откладывать = be postponing / postpone repeatedly / have a habit of postponing

They are in the accusative case because they are the direct object of отложить.

• отложить что? — postpone what?
• этот разговор — this conversation

However, for masculine inanimate nouns, the accusative looks exactly like the nominative:

• nominative: этот разговор
• accusative: этот разговор

So it may look unchanged, but grammatically it is accusative.

До завтра literally means until tomorrow.

The preposition до means until / up to / before, and it requires the genitive case.

With завтра, the form stays завтра, so you do not see a visible ending change here.

Examples:

• до вечера — until evening
• до понедельника — until Monday
• до завтра — until tomorrow

So:

• отложить до завтра = postpone until tomorrow

Here все means everyone.

Russian все can mean different things depending on context:

• всё (with stress on the final sound, usually written with ё) = everything
• все = everyone / all people

In this sentence, because it is followed by устали (got tired / are tired) in the plural, it clearly refers to people:

• если все уже устали = if everyone is already tired

So here все means everyone, not everything.

This is a very common point for English speakers.

Russian often uses the past tense form of verbs like устать to express a present state that resulted from becoming tired:

• устать = to get tired
• устали = got tired / have become tired

But in many contexts, устали is best translated simply as are tired.

So:

• если все уже устали
  literally: if everyone has already gotten tired
  natural English: if everyone is already tired

This is normal Russian usage. Compare:

• Я устал. — I’m tired.
• Она устала. — She’s tired.
• Мы устали. — We’re tired.

Even though the form is grammatically past tense, it often corresponds to present-state English.

Normally, Russian uses the short-result idea with the verb устать, not an adjective equivalent in this context.

The most natural way is:

• все уже устали

There is also the adjective усталый (tired), but it is used differently:

• усталый человек — a tired person
• он усталый — he looks tired / he is a tired person

But for the common everyday meaning someone is tired, Russian much more naturally says:

• он устал
• они устали

So in this sentence, если все уже устали is exactly what you would expect.

Уже means already.

It shows that by this point, the people have become tired:

• если все устали — if everyone is tired
• если все уже устали — if everyone is already tired

So уже adds the idea that the tiredness has already happened by now, which strengthens the reason for postponing the conversation.

Because если все уже устали is a subordinate clause:

• main clause: Лучше отложить этот разговор до завтра
• subordinate clause: если все уже устали

Russian normally separates such clauses with a comma.

So the comma here is standard punctuation, just as in English:

• It’s better to postpone this conversation until tomorrow, if everyone is already tired.

In Russian, the comma is generally required.

Yes. Russian word order is flexible, though the original version is very natural:

• Лучше отложить этот разговор до завтра, если все уже устали.

You could also hear:

• Если все уже устали, лучше отложить этот разговор до завтра.

This version puts the condition first and may sound a bit more logical or emphatic: If everyone is already tired, it’s better to postpone this conversation until tomorrow.

You can also move уже around a little, though not every position sounds equally natural.

The original sentence is neutral and smooth.

Разговор is a very common, neutral word meaning conversation or talk.

• разговор = general conversation / talk
• беседа = conversation, but often a bit more formal, calm, or deliberate
• дискуссия = discussion, often more formal or argumentative

In this sentence, этот разговор sounds natural because it refers to this particular conversation/topic we need to talk about.

It is a practical, everyday choice.

Yes, often that is a very natural translation.

Depending on context, these are all possible:

• It’s better to postpone...
• Better to postpone...
• We’d better postpone...

The Russian sentence itself is impersonal: it does not explicitly say we. But English often adds we because that is what is implied in context.

So:

• Лучше отложить этот разговор до завтра...
  can mean
  It’s better to postpone this conversation until tomorrow...
  or
  We’d better postpone this conversation until tomorrow...

Yes, very often it can.

Literally, отложить разговор means postpone the conversation. But in real usage, it can imply:

• postponing a planned conversation
• delaying discussion of a topic
• putting off addressing an issue

So depending on context, этот разговор may mean not just a chat, but this matter we need to discuss.

That is very natural in Russian.

Yes, absolutely.

There are two common ways to express this idea:

• отложить этот разговор до завтра
• перенести этот разговор на завтра

They are close, but there is a slight nuance:

• отложить = postpone / put off
• перенести на завтра = reschedule/move to tomorrow more explicitly

So:

• Лучше отложить этот разговор до завтра
  = Better postpone this conversation until tomorrow.
• Лучше перенести этот разговор на завтра
  = Better move this conversation to tomorrow.

Both are natural. The original sentence is slightly broader and less explicitly schedule-focused.

It is neutral. It works well in everyday speech and in writing.

Nothing in it is especially slangy, bookish, or highly formal. That makes it a very useful pattern to learn:

• Лучше + infinitive
• если + clause

So the whole sentence sounds natural in many ordinary situations.