Ο καφές στο καφενείο είναι δυνατός, γι’ αυτό πίνω μόνο μισό φλιτζάνι όταν έχω ήδη πιει εσπρέσο.

Because καφές is a masculine noun in Greek.

• ο καφές = the coffee
• τον καφέ = the coffee (object form)

In this sentence, ο καφές is the subject of the verb είναι:

• Ο καφές ... είναι δυνατός = The coffee ... is strong

So Greek uses the nominative form: ο καφές.

στο is a contraction of σε + το:

• σε = in / at / to
• το = the
• στο = in the / at the / to the

So:

• στο καφενείο = at the coffeehouse / in the café

A καφενείο is traditionally more like a Greek coffeehouse or local café, not just any modern coffee shop. Depending on context, English might translate it as café, coffeehouse, or local coffee shop.

Yes — and that is exactly why it works here.

δυνατός literally means strong, powerful, or intense. With coffee, it means the coffee is strong in taste/effect.

So:

• Ο καφές ... είναι δυνατός = The coffee ... is strong

Also notice agreement:

• καφές is masculine singular
• δυνατός is also masculine singular

Greek adjectives must agree with the noun they describe.

γι’ αυτό means that’s why, for this reason, or therefore.

It comes from για αυτό, but in normal writing and speech it is very often shortened to γι’ αυτό.

So:

• Ο καφές ... είναι δυνατός, γι’ αυτό...
• The coffee ... is strong, so/that’s why...

The apostrophe shows that a vowel has been dropped in the shortened form.

Because πίνω here expresses a habitual or general action, not a one-time future action.

• πίνω = I drink / I am drinking
• θα πιω = I will drink

In this sentence, the speaker is saying what they generally do in that situation:

• γι’ αυτό πίνω μόνο μισό φλιτζάνι...
• that’s why I only drink half a cup...

So the Greek present tense works like English I drink in statements about habits.

μισό means half, and here it agrees with φλιτζάνι.

• φλιτζάνι = cup
• It is neuter singular
• So μισός / μισή / μισό changes to match the noun
• Here we need μισό φλιτζάνι

The whole phrase means:

• μόνο μισό φλιτζάνι = only half a cup

Also, this phrase is the direct object of πίνω:

• πίνω μισό φλιτζάνι = I drink half a cup

Greek often leaves out the article in expressions like this when the meaning is indefinite or more quantity-based.

So:

• πίνω μόνο μισό φλιτζάνι = I only drink half a cup

This sounds natural because the focus is on how much is drunk, not on a specific cup already known to the listener.

If you added an article, the meaning would feel more specific or context-dependent.

This means when I have already drunk or more naturally in English, when I’ve already had.

It contains:

• όταν = when
• έχω = I have
• ήδη = already
• πιει = drunk (past participle form used with έχω)

So έχω πιει is the perfect form in Modern Greek, built with:

• έχω + participle

It describes an action that has already been completed by that point:

• όταν έχω ήδη πιει εσπρέσο
• when I’ve already had espresso

Because πιει and πιω are different forms.

• πιει = participle used with έχω
• πιω = a different verb form used after να, θα, etc.

Compare:

• έχω πιει = I have drunk / I’ve had
• θα πιω = I will drink
• να πιω = that I drink / to drink in subjunctive-type uses

So in this sentence, since the structure is έχω ήδη..., the correct form is:

• έχω ήδη πιει

not έχω ήδη πιω.

Because Greek often omits the article with foods and drinks when speaking in a general or indefinite way.

So:

• έχω ήδη πιει εσπρέσο = I’ve already had espresso

This sounds natural if the speaker means espresso as a drink/serving, without emphasizing a specific one.

You might also hear:

• έχω ήδη πιει έναν εσπρέσο = I’ve already had an espresso

That version makes the countable “one espresso” idea more explicit.

Also, εσπρέσο is a loanword and is commonly treated as an indeclinable form in everyday use.

Greek word order is more flexible than English word order, but the version in the sentence is very natural.

The sentence is:

• Ο καφές στο καφενείο είναι δυνατός, γι’ αυτό πίνω μόνο μισό φλιτζάνι όταν έχω ήδη πιει εσπρέσο.

This order works well because:

1. Ο καφές στο καφενείο sets the topic
2. είναι δυνατός gives the description
3. γι’ αυτό introduces the result
4. όταν έχω ήδη πιει εσπρέσο gives the condition/time frame

Greek could move parts around for emphasis, but the meaning would stay similar. For example, μόνο could move depending on what the speaker wants to stress. Still, the original sentence is the most straightforward neutral phrasing.

ήδη means already, and in Greek it often appears between έχω and the participle:

• έχω ήδη πιει = I have already drunk / I’ve already had

That is a very common and natural position.

You may also hear slight variations in speech, but έχω ήδη πιει is standard and clear.

Yes, depending on context.

In this sentence, όταν introduces a repeated situation, so English could understand it as either:

• when I’ve already had espresso
• whenever I’ve already had espresso

Because the main verb πίνω is habitual, the whole sentence describes what the speaker usually does in that situation. So όταν here has a slightly repeated/habitual feel, even though the basic meaning is still simply when.