Το απόγευμα δεν πίνω καφέ, γιατί το βράδυ δεν κοιμάμαι καλά.

In Greek, expressions of time often use the definite article + a noun:

• το απόγευμα = in the afternoon / during the afternoon
• το βράδυ = at night / in the evening

So here το does not mean the in a very literal English way. It is just the normal Greek pattern for many time expressions.

You will see this a lot:

• το πρωί = in the morning
• το μεσημέρι = at noon / in the midday period
• το απόγευμα = in the afternoon
• το βράδυ = in the evening / at night

English usually does not use an article in these phrases, but Greek often does.

δεν is the normal word for not before verbs in Greek.

So:

• πίνω = I drink
• δεν πίνω = I do not drink

and

• κοιμάμαι = I sleep
• δεν κοιμάμαι = I do not sleep

In this sentence, δεν comes directly before the verb each time:

• δεν πίνω
• δεν κοιμάμαι

That is the basic pattern for negation in everyday Greek.

Because Greek uses the present tense for habitual actions, just like English often does.

So:

• Το απόγευμα δεν πίνω καφέ means I don’t drink coffee in the afternoon
• το βράδυ δεν κοιμάμαι καλά means I don’t sleep well at night

This is not necessarily about right now. It can describe what usually happens. In other words, the Greek present tense can mean:

• what I am doing now, or
• what I generally do

The time expressions το απόγευμα and το βράδυ help show that this is a repeated, habitual situation.

Because καφέ here means coffee in general, not a specific coffee.

• πίνω καφέ = I drink coffee / I have coffee
• πίνω τον καφέ = I drink the coffee

In your sentence, the speaker is talking about coffee as a general thing, so Greek normally leaves out the article.

This is very common with food and drink:

• τρώω ψωμί = I eat bread
• πίνω γάλα = I drink milk
• πίνω καφέ = I drink coffee

If you add the article, it usually sounds more specific.

Yes — the dictionary form is ο καφές.

But in the sentence, καφέ is the accusative singular, because it is the direct object of πίνω.

So:

• ο καφές = coffee, the coffee, as the subject
• τον καφέ / καφέ = coffee, as the object

Examples:

• Ο καφές είναι ζεστός. = The coffee is hot.
• Πίνω καφέ. = I drink coffee.

This is a very common pattern with masculine nouns ending in -ές.

Yes. γιατί can mean both:

• because
• why

In this sentence, it means because:

• δεν πίνω καφέ, γιατί το βράδυ δεν κοιμάμαι καλά
• I don’t drink coffee in the afternoon, because I don’t sleep well at night

As a question word, it can also mean why:

• Γιατί δεν πίνεις καφέ; = Why don’t you drink coffee?

So the meaning depends on context and punctuation.

κοιμάμαι is the normal modern Greek verb for sleep.

Its basic meaning is:

• κοιμάμαι = I sleep / I am sleeping

It is a very common verb and it belongs to a group of verbs that look like middle/passive forms in Greek, even when the meaning is active in English.

So although English says I sleep, Greek says κοιμάμαι, not something based on κοιμώ in this meaning.

You should simply learn κοιμάμαι as the normal verb for to sleep.

Yes. Here καλά means well, and it works like an adverb describing how someone sleeps.

So:

• κοιμάμαι καλά = I sleep well
• δεν κοιμάμαι καλά = I don’t sleep well

This is very natural Greek.

A few similar examples:

• μιλάω καλά ελληνικά = I speak Greek well
• δουλεύει καλά = it works well
• νιώθω καλά = I feel well / I feel good

So καλά is a very useful word.

They refer to different parts of the day:

• το απόγευμα = the afternoon
• το βράδυ = the evening / night

A simple way to think of them:

• απόγευμα starts after midday and before night
• βράδυ is later, when it is evening or nighttime

In the sentence, the contrast is important:

• Το απόγευμα δεν πίνω καφέ = I don’t drink coffee in the afternoon
• γιατί το βράδυ δεν κοιμάμαι καλά = because at night / in the evening I don’t sleep well

So the idea is: drinking coffee later in the day affects sleep later that night.

Greek word order is often more flexible than English word order. The sentence you have is very natural, but some parts could move for emphasis.

The basic sentence is:

• Το απόγευμα δεν πίνω καφέ, γιατί το βράδυ δεν κοιμάμαι καλά.

You could also hear things like:

• Δεν πίνω καφέ το απόγευμα, γιατί το βράδυ δεν κοιμάμαι καλά.

That still means the same thing.

Greek often moves time expressions like το απόγευμα and το βράδυ around depending on emphasis, rhythm, or style. But for a learner, the version you have is a very good standard pattern.

Greek does not need an extra word like so here, because γιατί already introduces the reason.

The structure is:

• statement
• γιατί
  • reason

So:

• Δεν πίνω καφέ το απόγευμα, γιατί το βράδυ δεν κοιμάμαι καλά.
• I don’t drink coffee in the afternoon, because I don’t sleep well at night.

The logic is clear without adding anything else.

If you wanted a different structure in English, you might say:

• I don’t sleep well at night, so I don’t drink coffee in the afternoon.

Greek could express that too, but your sentence is built around because.

Most naturally, it describes a usual pattern or personal habit.

That feeling comes from:

• the present tense: πίνω, κοιμάμαι
• the general time expressions: το απόγευμα, το βράδυ
• the general noun: καφέ

So the sentence sounds like:

• As a rule, I don’t drink coffee in the afternoon, because I don’t sleep well at night.

If someone wanted to refer to one specific day, Greek would usually add clearer context.

Not necessarily. These phrases are flexible, and the best English translation depends on context.

For example:

• το απόγευμα can be in the afternoon
• το βράδυ can be in the evening or at night

In your sentence, το βράδυ δεν κοιμάμαι καλά is often best understood as at night I don’t sleep well, because sleep is involved.

So when reading Greek, it is better to understand the time period first, and then choose the most natural English wording for that situation.