Περπάτησα πέντε χιλιόμετρα.

Greek often does not need a separate subject pronoun because the verb ending already shows the person and number.

• Περπάτησα = I walked
• The ending -α here tells you it is 1st person singular: I

So Περπάτησα πέντε χιλιόμετρα is a complete sentence by itself.

You can add εγώ if you want emphasis or contrast:

• Εγώ περπάτησα πέντε χιλιόμετρα, όχι αυτός.
  I walked five kilometers, not him.

Without emphasis, Greek usually leaves εγώ out.

Περπάτησα is the aorist form of the verb περπατάω / περπατώ.

In this sentence, the aorist expresses a completed action in the past:

• Περπάτησα = I walked

It does not focus on the action as ongoing or repeated. It presents it as a whole event.

So this sentence sounds like:

• I walked five kilometers
• not I was walking five kilometers

This is a very common question because Greek makes an important distinction here.

• Περπάτησα = I walked
  a completed event
• Περπατούσα = I was walking / I used to walk
  ongoing, repeated, or background action in the past

Compare:

• Χθες περπάτησα πέντε χιλιόμετρα.
  Yesterday I walked five kilometers.
  → one completed action

• Όταν με είδες, περπατούσα.
  When you saw me, I was walking.
  → action in progress

So in your sentence, Περπάτησα is used because the speaker is talking about a finished result: five kilometers walked.

It comes from the verb περπατάω / περπατώ = to walk.

The aorist stem is περπάτησ-, and then Greek adds the ending for I:

• περπάτησ-
• -α

So:

• περπάτησα = I walked

This is a very common aorist pattern in Greek.

This is the normal Greek way to express distance.

• πέντε = five
• χιλιόμετρα = kilometers

So Greek simply puts the number before the noun:

• ένα χιλιόμετρο = one kilometer
• δύο χιλιόμετρα = two kilometers
• πέντε χιλιόμετρα = five kilometers

After numbers greater than one, χιλιόμετρο appears here as χιλιόμετρα, the plural form.

Χιλιόμετρο is a neuter noun.

Its forms are:

• singular: το χιλιόμετρο
• plural: τα χιλιόμετρα

In this sentence, χιλιόμετρα is in the plural, because the number is five.

Also, with neuter nouns, the nominative plural and accusative plural are the same form:

• χιλιόμετρα

That is why the form looks simple here.

It is best understood as a measure of distance connected to the verb walked.

In English, we also say:

• I walked five kilometers

Greek does the same thing very naturally, without needing a preposition.

So yes, it behaves a lot like a direct object in structure, but semantically it is really telling you how far the person walked.

Because Greek normally expresses distance traveled directly, without a preposition.

So:

• Περπάτησα πέντε χιλιόμετρα.
  I walked five kilometers.

This is the standard pattern.

That is different from many expressions of duration, where Greek often uses για:

• Περπάτησα για δύο ώρες.
  I walked for two hours.

So a useful contrast is:

• distance → no preposition: πέντε χιλιόμετρα
• duration → often για: για δύο ώρες

Yes. Greek word order is more flexible than English word order.

The neutral order here is:

• Περπάτησα πέντε χιλιόμετρα.

But you may also hear:

• Πέντε χιλιόμετρα περπάτησα.

That version puts more emphasis on πέντε χιλιόμετρα, as if saying:

• It was five kilometers that I walked

So the original order is the most neutral and natural for a simple statement.

A simple English-friendly approximation is:

• pehr-PAH-tee-sa PEN-deh hee-lee-OH-meh-tra

A few helpful notes:

• Περπάτησα has the stress on πά
• πέντε has the stress on πέν
• χιλιόμετρα has the stress on ό

Also:

• χ is not like English h exactly; it is a rougher sound, like the ch in German Bach or Scottish loch
• ντ in πέντε is often pronounced like nd

Yes, in writing you can use abbreviations or numerals:

• Περπάτησα 5 χλμ.

That means the same thing as:

• Περπάτησα πέντε χιλιόμετρα.

But in normal teaching materials, full words are usually better because they help you learn spelling and grammar.

Both are used.

They are two common forms of the same verb:

• περπατάω
• περπατώ

Both mean to walk.

In everyday Greek, many verbs have this kind of double form. A learner will often see both in dictionaries and textbooks.

For your sentence, the aorist Περπάτησα can be associated with either present form:

• περπατάω → περπάτησα
• περπατώ → περπάτησα

No. Περπάτησα is specifically past.

For the present, you would use:

• Περπατάω πέντε χιλιόμετρα.
• or Περπατώ πέντε χιλιόμετρα.

That means:

• I walk five kilometers
• or, depending on context, I am walking five kilometers

So the key contrast is:

• Περπάτησα = I walked
• Περπατάω / Περπατώ = I walk / I am walking