Kannst du das bitte noch einmal erklären?

Because this is a yes/no question in German. In that kind of question, the conjugated verb usually comes first.

• Statement: Du kannst das noch einmal erklären.
• Question: Kannst du das noch einmal erklären?

So kannst is first because the speaker is asking for confirmation or a response like yes or no.

Kannst is the 2nd person singular form of können, which means can or to be able to.

The verb können changes like this in the present tense:

• ich kann
• du kannst
• er/sie/es kann
• wir können
• ihr könnt
• sie/Sie können

So Kannst du ...? means Can you ...? when speaking to one person informally.

Du is the informal word for you when talking to one person.

German distinguishes between:

• du = informal singular you
• Sie = formal you

So:

• Kannst du das bitte noch einmal erklären? = informal
• Können Sie das bitte noch einmal erklären? = formal

A learner often needs to choose between these depending on the situation and the relationship between the speakers.

Here das means that or it, referring to something that was just said or explained.

It is the direct object of erklären:

• explain what?
• explain that / it = das

So the sentence is asking someone to explain a particular thing again.

Both das and es can sometimes be translated as it, but they are not always used in the same way.

In this sentence, das points more clearly to a specific thing that was said, shown, or discussed. It often sounds more natural when referring back to an idea or explanation.

• Kannst du das noch einmal erklären? = Can you explain that again?
• Kannst du es noch einmal erklären? is also possible in some contexts, but das is very common when pointing back to something just mentioned.

So das often works like that thing / what you just said.

Bitte makes the request more polite. It is like saying please.

Without bitte:

• Kannst du das noch einmal erklären?

With bitte:

• Kannst du das bitte noch einmal erklären?

The version with bitte sounds friendlier and more natural in many situations.

Noch einmal means once again, one more time, or simply again.

• noch = still / yet / another
• einmal = once / one time

Together, noch einmal means one more time.

In everyday speech, you will also often hear:

• nochmal
• noch mal

These are common spoken or less formal written alternatives to noch einmal.

Because können is a modal verb, and in German modal verbs usually send the second verb to the end of the clause in its infinitive form.

Here:

• kannst = the conjugated modal verb
• erklären = the main verb in the infinitive

So the pattern is:

• Kannst du ... erklären?

This is very common in German:

• Kannst du kommen?
• Willst du helfen?
• Musst du arbeiten?

It is in the accusative case because it is the direct object of erklären.

You can ask:

• Was kannst du erklären?
• Das.

So das is the thing being explained, which makes it accusative.

Yes, absolutely. Nochmal is very common in everyday German and means the same thing here as noch einmal.

So these are both natural:

• Kannst du das bitte noch einmal erklären?
• Kannst du das bitte nochmal erklären?

The version with noch einmal can sound a little more careful or neutral, while nochmal is especially common in spoken German.

Grammatically, it is a question, because it uses the yes/no question structure:

• Kannst du ...?

But in real use, it often functions as a polite request rather than a literal question about ability.

So the speaker usually does not mean Are you capable of explaining it again?
They usually mean Please explain it again.

This is similar to English Can you explain that again, please?

Sometimes, yes, but noch einmal is usually the more natural choice when asking someone to repeat an explanation.

• noch einmal erklären = explain it one more time
• wieder erklären = explain it again

Both can work, but noch einmal often sounds better when you want someone to repeat something for your benefit.

So learners will most often hear:

• Kannst du das bitte noch einmal erklären?

You would change du to Sie, and the verb would change to match:

• Kannst du das bitte noch einmal erklären? = informal
• Können Sie das bitte noch einmal erklären? = formal

Notice the verb change:

• du kannst
• Sie können

Everything else can stay the same.