Новая грамматическая тема: союз «раз уж» помогает показать, что раз что-то уже решено или начато, следующий шаг кажется естественным.

Раз уж is a conjunction-like expression meaning something like:

• since
• now that
• if ... already
• seeing that

Its special nuance is this: something is already decided, true, or underway, so the next step feels natural, logical, or unavoidable.

For example:

• Раз уж начали, надо закончить.
  Since we’ve already started, we should finish.

• Раз уж ты здесь, помоги мне.
  Since you’re here anyway, help me.

So it often carries the feeling of “well, given that this is already the case...”

Раз by itself can also mean since or if, especially in colloquial Russian:

• Раз ты знаешь, объясни.
  Since you know, explain.

When you add уж, the meaning becomes more emphatic and more specific. Раз уж suggests:

• the situation is already settled
• the speaker is accepting that fact
• the consequence feels natural or expected

Compare:

• Раз ты пришёл, проходи.
  Since you came, come in.
  Neutral colloquial cause.

• Раз уж ты пришёл, проходи.
  Since you’re here anyway, come in.
  Stronger sense of “well, now that that has happened...”

So раз уж is usually more expressive than plain раз.

In раз уж, уж is not functioning like a full independent word with a simple one-word translation. It adds emphasis and a feeling of:

• acceptance
• inevitability
• “given that this is already the case”

It often makes the phrase sound a little like:

• well, since...
• now that...
• if we’re already doing this...

So in:

• Раз уж решили, надо действовать.

the speaker is not just stating a reason. They are saying that because the decision has already been made, acting now is the natural next step.

Not exactly.

• Раз уж is a common fixed expression.
• Уж here is a particle.
• Уже is the adverb meaning already.

A learner should treat раз уж as its own useful expression.

Sometimes раз уже is also possible in a sentence where уже keeps its normal meaning of already, but it is not quite the same thing stylistically. In many everyday cases, Russian speakers naturally prefer раз уж.

So as a rule of thumb:

• learn раз уж as a set phrase
• do not automatically replace it with раз уже

It is mostly neutral to conversational.

That means:

• very common in speech
• natural in informal writing
• acceptable in many everyday written contexts

But it is usually less formal than words like:

• поскольку
• так как

Compare:

• Поскольку решение уже принято, следует перейти к следующему этапу.
  More formal.

• Раз уж решение принято, надо переходить к следующему этапу.
  More natural in everyday speech.

So раз уж is not slang, but it does sound more personal and spoken.

It usually introduces the clause that gives the reason or background.

Very often it comes at the beginning:

• Раз уж ты начал, заканчивай.
• Раз уж мы приехали, давай останемся.

But it can also come later:

• Заканчивай, раз уж ты начал.
• Давай останемся, раз уж мы приехали.

So the pattern is often:

• Раз уж + clause, main clause
• or Main clause, раз уж + clause

Yes, normally yes.

Because раз уж introduces a subordinate clause, it is usually separated by a comma:

• Раз уж ты пришёл, садись.
• Садись, раз уж ты пришёл.

So if you use it to connect two parts of a sentence, expect standard comma punctuation.

Раз уж is especially common when talking about something that is:

• already decided
• already started
• already true
• impossible to undo easily

That is why it often appears with ideas like:

• решили — decided
• начали — started
• пришёл — came
• купили — bought
• сделал — did

Examples:

• Раз уж начали ремонт, надо довести его до конца.
• Раз уж купил, пользуйся.
• Раз уж пришли, не будем сразу уходить.

Perfective verbs are common because they often show a completed step that creates the new situation, but раз уж is not limited to perfective verbs.

Yes, very often.

Depending on context and intonation, раз уж can sound like:

• practical acceptance
• mild insistence
• resignation
• “well, since that’s how it is...”

For example:

• Раз уж согласился, работай.
  This can sound like: Well, you agreed, so now do the work.

• Раз уж поехали, не будем возвращаться.
  Well, since we’ve already set off, let’s not turn back.

So it is not always emotionally neutral. It often carries the speaker’s attitude toward the situation.

Yes — very naturally.

In fact, that is one of its most common uses. The first clause gives the accepted situation, and the second clause gives the logical next step:

• Раз уж ты здесь, помоги.
• Раз уж начали, давай закончим.
• Раз уж решил учить русский, занимайся регулярно.

This is why раз уж is so useful: it often links an established fact with a recommendation, command, or conclusion.

There is no single perfect translation for every sentence. Common English equivalents are:

• since
• now that
• seeing that
• if ... already
• if we’re already...
• well, since...

The best choice depends on the tone.

For example:

• Раз уж ты дома, приготовь ужин.
  Since you’re home, make dinner.

• Раз уж начали спорить, давай разберёмся до конца.
  Now that we’ve started arguing, let’s sort it out completely.

• Раз уж всё решено, ничего не поделаешь.
  Since everything is already decided, there’s nothing to be done.

So it is better to learn the idea behind раз уж than to memorize only one English word.