Ich zeichne das Schnäppchen mit fünf Euro aus.

Because the verb here is auszeichnen, which is a separable verb.

In a normal main clause, German often splits separable verbs:

• Ich zeichne ... aus.

So:

• zeichne = the conjugated verb part
• aus = the separable prefix, which moves to the end

Compare:

• Ich zeichne das Schnäppchen mit fünf Euro aus.
• Ich will das Schnäppchen mit fünf Euro auszeichnen.

In the second sentence, because there is an infinitive, the verb stays together as auszeichnen.

The real verb is auszeichnen.

That matters because separable-prefix verbs often have meanings that are quite different from the simple base verb.

• zeichnen = to draw
• auszeichnen = a different verb with its own meaning

So you should learn auszeichnen as one vocabulary item, not as just zeichnen plus a random aus.

Because Schnäppchen is a neuter noun, so its article is das.

A very helpful clue is the ending -chen:

• Nouns ending in -chen are always neuter in German.

For example:

• das Mädchen
• das Häuschen
• das Schnäppchen

So even if the original word might have had a different gender, the -chen ending makes it neuter.

Because it is the direct object of the verb auszeichnen.

In the sentence:

• Ich = the subject
• zeichne ... aus = the verb
• das Schnäppchen = the thing being affected by the verb

That makes das Schnäppchen accusative.

In this particular noun phrase, das looks the same in nominative and accusative, so you do not see a form change:

• nominative: das Schnäppchen
• accusative: das Schnäppchen

But its role in the sentence is accusative.

Because mit is a preposition that always takes the dative case.

So:

• mit fünf Euro

This phrase tells you the means, amount, or accompanying detail, depending on the meaning shown to the learner.

A key point is:

• after mit, you expect dative

With a numeral and a currency amount, German normally just uses:

• fünf Euro not something like fünf Euros

In standard German, after numbers, currency names like Euro usually stay unchanged:

• ein Euro
• zwei Euro
• fünf Euro

So Euro often behaves like a fixed unit word in amounts.

You may sometimes hear nonstandard forms in casual speech, but for learners, the safe standard form is:

• fünf Euro

Because German usually does not use an article in simple expressions of amount after a number.

So you say:

• mit fünf Euro not usually
• mit den fünf Euro unless you mean some specific five euros already known in the conversation

Compare:

• Ich bezahle mit fünf Euro. = just an amount
• Ich bezahle mit den fünf Euro, die du mir gegeben hast. = those specific five euros

Because the verb is being conjugated for:

• 1st person singular = ich
• present tense

The present-tense forms of auszeichnen are:

• ich zeichne ... aus
• du zeichnest ... aus
• er/sie/es zeichnet ... aus
• wir zeichnen ... aus
• ihr zeichnet ... aus
• sie/Sie zeichnen ... aus

So ich takes zeichne.

Yes, German word order is flexible, but the conjugated verb still usually stays in second position in a main clause, and the separable prefix still goes to the end.

For example, you could also say:

• Mit fünf Euro zeichne ich das Schnäppchen aus.

That emphasizes mit fünf Euro more strongly.

But you still keep:

• zeichne in second position
• aus at the end

No. It stays split mainly in main clauses.

It does not stay split in several other structures, such as:

• infinitive:
  Ich will das Schnäppchen mit fünf Euro auszeichnen.

• perfect tense:
  Ich habe das Schnäppchen mit fünf Euro ausgezeichnet.

• subordinate clause:
  ..., weil ich das Schnäppchen mit fünf Euro auszeichne.

So this split form is not random; it depends on sentence structure.

Because in German, all nouns are capitalized.

So in this sentence:

• Ich = capitalized because it begins the sentence
• Schnäppchen = capitalized because it is a noun
• Euro = capitalized because it is also a noun

This is a standard rule in German spelling and is something English speakers often need to get used to.