Δεν πιστεύω τη δικαιολογία.

Δεν is the standard negation word for many Greek verb forms. It means not.

So:

• Πιστεύω = I believe
• Δεν πιστεύω = I do not believe / I don’t believe

In Greek, δεν usually comes directly before the verb.

The verb πιστεύω is in the 1st person singular, present tense, so it means I believe.

The ending -ω is a very common ending for I in Greek verbs.

For example:

• πιστεύω = I believe
• πιστεύεις = you believe
• πιστεύει = he/she/it believes

Greek often shows the subject through the verb ending, so you do not need to add the pronoun εγώ (I) unless you want emphasis.

Because Greek normally drops subject pronouns when they are not needed.

So Greek says:

• Δεν πιστεύω τη δικαιολογία.

rather than:

• Εγώ δεν πιστεύω τη δικαιολογία.

Both are possible, but the second one sounds more emphatic, like I don’t believe the excuse.

τη means the here, so τη δικαιολογία means the excuse.

Greek often uses the definite article where English does, and sometimes even where English might leave it out.

In this sentence, the speaker is talking about a specific excuse, so the excuse is natural.

Because δικαιολογία is the direct object of the verb πιστεύω, so it must be in the accusative case, not the nominative.

For this feminine singular noun:

• η δικαιολογία = the excuse, as the subject
• τη(ν) δικαιολογία = the excuse, as the object

Here, the speaker is not saying the excuse believes something. The speaker is saying I don’t believe the excuse, so the noun is an object.

Both τη and την can represent the feminine accusative singular article.

The full form is την, but in everyday speech and writing, the final -ν is often dropped before certain consonants.

Since δικαιολογία begins with δ, it is very common to write:

• τη δικαιολογία

You may also sometimes see την δικαιολογία, especially in more careful or formal writing, but τη δικαιολογία is very normal.

δικαιολογία means excuse, justification, or explanation offered to defend oneself.

In this sentence, it most naturally means excuse.

So Δεν πιστεύω τη δικαιολογία means that the speaker thinks the explanation is not true or not convincing.

Not always. πιστεύω can be used in different ways.

1. πιστεύω + direct object (accusative)
   This often means believe what someone says / accept something as true.
   Example:

   • Δεν πιστεύω τη δικαιολογία. = I don’t believe the excuse.

2. πιστεύω σε + accusative
   This means believe in someone or something.
   Example:

   • Πιστεύω σε σένα. = I believe in you.

3. πιστεύω ότι...
   This means I think / I believe that...
   Example:

   • Πιστεύω ότι λέει ψέματα. = I believe that he/she is lying.

So here, πιστεύω is being used in the sense of accept as true.

Greek word order is more flexible than English word order.

The neutral order here is:

• Δεν πιστεύω τη δικαιολογία.

But Greek can move things around for emphasis. For example:

• Τη δικαιολογία δεν πιστεύω.
  This puts emphasis on the excuse.

Even so, the original sentence is the most natural basic version.

A rough pronunciation is:

Then pee-STEH-vo tee thee-keh-o-loh-YEE-ah

A few helpful notes:

• δ sounds like the th in this
• ει in πιστεύω sounds like ee
• γ before ι/ε is softer, somewhat like a y-sound mixed with a light fricative
• The stressed syllables are:
  • πισ in πιστεύω
  • γί in δικαιολογία

A more careful breakdown:

• Δεν = then
• πιστεύω = pee-STEV-o
• τη = tee
• δικαιολογία = thee-keh-o-loh-YEE-ah

Greek uses accent marks to show which syllable is stressed.

So:

• Δεν has stress on its only syllable
• πιστεύω is stressed on -τεύ-
• δικαιολογία is stressed on -γί-

Stress is important in Greek pronunciation, and it is written clearly, unlike in English.

Possibly in some contexts, but I don’t believe the excuse is the most direct and natural translation.

Πιστεύω here means believe / accept as true, not really trust in the broader personal sense.

If you wanted to talk about trusting a person, Greek might use other structures depending on the context.

It is neutral and completely natural in everyday Greek.

There is nothing especially formal or informal about it. It could be used in normal conversation, writing, or speech.

Yes. The plural would be:

• οι δικαιολογίες = the excuses
• Δεν πιστεύω τις δικαιολογίες. = I don’t believe the excuses.

So the article and noun both change to match plural accusative feminine:

• singular: τη δικαιολογία
• plural: τις δικαιολογίες