Если тебе нечего сказать, лучше молчать.

Because Russian uses the pattern кому нечего + infinitive.

So тебе нечего сказать literally means something like:

• to you there is nothing to say

The person involved goes in the dative case, so:

• я → мне
• ты → тебе
• он → ему
• она → ей

This is a very common Russian structure:

• Мне нечего делать — I have nothing to do.
• Ему некого спросить — He has no one to ask.

Нечего means there is nothing to... or nothing ... to do/say/etc.

In this sentence:

• нечего сказать = nothing to say

It is a fixed Russian form used with an infinitive. Similar words are:

• некого — no one to...
• негде — nowhere to...
• некуда — nowhere to go
• незачем — no reason to...

So Если тебе нечего сказать... is a very natural way to say If you have nothing to say...

Both verbs relate to speaking, but they are not the same.

• сказать = to say, to express something конкретely, often one complete utterance
• говорить = to speak, to talk, to be speaking in general

In нечего сказать, Russian normally uses сказать because the idea is:

• you have no specific thing to say

If you used говорить, it would sound less natural here or would shift the nuance.

Compare:

• Мне нечего сказать — I have nothing to say.
• Я люблю говорить — I like talking.

So сказать is the standard choice in this sentence.

Because the sentence is about a single complete act of saying something, not about an ongoing process.

Russian aspect matters even in infinitives:

• сказать (perfective) = to say something once, to make a complete utterance
• говорить (imperfective) = to speak/talk, as a process or repeated action

Here the idea is not if you have no ability to keep talking, but rather:

• if you have no actual point or remark to make

That fits сказать very well.

Here лучше means it is better to...

So:

• лучше молчать = it is better to stay silent

This is a very common Russian pattern:

• лучше + infinitive

Examples:

• Лучше подождать — It’s better to wait.
• Лучше уйти сейчас — It’s better to leave now.

In your sentence, лучше gives advice or a general recommendation.

Because молчать is the infinitive, and the structure is:

• лучше + infinitive

So the sentence means:

• it’s better to be silent

If you said молчи, that would be the imperative:

• Молчи! — Be quiet! / Shut up!

That sounds much more direct and forceful.

So compare:

• Лучше молчать — It’s better to stay silent.
• Молчи — Be silent.

The original sentence is advice, not a command.

Yes, you can think of it that way.

The full idea is:

• Если тебе нечего сказать, (тебе) лучше молчать.

Russian often omits repeated words when they are obvious from context.

So the second clause does not need to repeat тебе, because it is already clear that the advice is addressed to the same person.

You could say:

• Если тебе нечего сказать, тебе лучше молчать.

But it sounds a bit heavier. The version without the second тебе is smoother and more natural.

Because Если introduces a subordinate clause:

• Если тебе нечего сказать = if you have nothing to say

Then the main clause follows:

• лучше молчать = it is better to stay silent

In Russian, clauses with если are separated by a comma.

So:

• Если тебе нечего сказать, лучше молчать.

That comma is required.

No, that is not correct.

In this construction, Russian uses нечего + infinitive, not ничего + infinitive.

So:

• тебе нечего сказать — correct
• тебе ничего сказать — incorrect in this meaning

Why? Because нечего is a special word used in patterns like:

• нечего делать
• нечего терять
• нечего добавить

By contrast, ничего is usually used differently, for example:

• Я ничего не сказал — I said nothing.
• Здесь ничего нет — There is nothing here.

So in your sentence, нечего is the right form.

Yes. Russian word order is flexible.

For example, these are possible:

• Если тебе нечего сказать, лучше молчать.
• Лучше молчать, если тебе нечего сказать.

The meaning stays basically the same, but the emphasis changes slightly.

The original version is very natural because it first gives the condition:

• If you have nothing to say...

and then the conclusion:

• ...it’s better to stay silent.

That order sounds especially natural for advice or a proverb-like statement.

It can be addressed to one person because of тебе, but it also has a general, proverb-like feel.

Russian often uses this kind of structure for broad advice:

• Если не знаешь, лучше спросить.
• Если устал, лучше отдохнуть.

So Если тебе нечего сказать, лучше молчать can mean:

• direct advice to one person
• a general truth about how one should behave

Because it uses infinitives and avoids a direct command, it sounds more like wisdom or advice than an order.

Yes, absolutely.

That version removes тебе and makes the sentence even more general:

• Если нечего сказать, лучше молчать = If there’s nothing to say, it’s better to stay silent.

With тебе, it is more directly aimed at you.

Without тебе, it sounds more universal and impersonal, almost like a saying.

So both are correct:

• Если тебе нечего сказать, лучше молчать. — directed at you
• Если нечего сказать, лучше молчать. — more general

A natural stressed version is:

• Е́сли тебе́ не́чего сказа́ть, лу́чше молча́ть.

Main stresses:

• Е́сли
• тебе́
• не́чего
• сказа́ть
• лу́чше
• молча́ть

A rough pronunciation guide for an English speaker:

• YES-lee tye-BYE NYE-che-va ska-ZAT', LOO-chshee mal-CHAT'

A few notes:

• чего in нечего is pronounced more like -чево, not a clear -go
• лучше has the чш sound cluster, which may take practice
• final ть in infinitives is soft

You do not need to pronounce every vowel exactly as written in slow, careful spelling; in natural Russian, unstressed vowels are reduced.