Γίνομαι νευρικός όταν πίνω πολύ καφέ.

Greek often leaves out the subject pronoun when it is obvious from the verb ending.

Here, both γίνομαι and πίνω are 1st person singular, so a Greek speaker already knows the subject is I.

• γίνομαι = I become / I get
• πίνω = I drink

You could add εγώ for emphasis, but it is not necessary:

• Εγώ γίνομαι νευρικός όταν πίνω πολύ καφέ.

That sounds more like I get nervous..., with extra emphasis on the speaker.

Γίνομαι means I become / I get, while είμαι means I am.

So:

• Γίνομαι νευρικός = I get nervous / I become nervous
• Είμαι νευρικός = I am nervous

In this sentence, the idea is that drinking a lot of coffee causes a change of state, so γίνομαι is the natural choice.

A native English speaker can think of it as the difference between:

• I am nervous when...
• I get nervous when...

Both can make sense in English, but Greek γίνομαι strongly suggests becoming nervous as a result.

Γίνομαι is:

• present tense
• 1st person singular
• the dictionary form of the verb γίνομαι

It has middle/passive-style endings, but its meaning here is active: I become / I get.

This is normal in Greek. Some verbs look passive in form but are active in meaning.

Νευρικός is an adjective, and adjectives in Greek change to agree with the person they describe.

Here it agrees with the speaker:

• νευρικός = masculine singular
• νευρική = feminine singular
• νευρικό = neuter singular

So a man would normally say:

• Γίνομαι νευρικός...

A woman would normally say:

• Γίνομαι νευρική...

Also, after γίνομαι, Greek uses the adjective in the nominative, because it describes the subject.

Often yes, but the meaning can be a bit broader.

Νευρικός can mean:

• nervous
• tense
• edgy
• jittery
• high-strung

In a sentence about coffee, it can sound very natural as jittery or on edge, not just emotionally nervous.

So in context, Γίνομαι νευρικός όταν πίνω πολύ καφέ can suggest:

• I get nervous
• I get jittery
• I get edgy

Όταν means when.

In this sentence, it introduces the time clause:

• όταν πίνω πολύ καφέ = when I drink a lot of coffee

With the present tense, όταν often gives a habitual or whenever meaning:

• When / Whenever I drink a lot of coffee, I get nervous.

So this sentence is not about one single occasion. It describes a general pattern.

Because the sentence describes a general repeated situation, not one single completed event.

• πίνω = I drink / I am drinking

After όταν, the present tense often means whenever something happens regularly:

• Όταν πίνω πολύ καφέ, γίνομαι νευρικός.
• Whenever I drink a lot of coffee, I get nervous.

If you wanted to talk about one future occasion, Greek would use a different structure, for example:

• Όταν πιω πολύ καφέ, θα γίνω νευρικός.
• When I drink a lot of coffee / once I’ve drunk a lot of coffee, I’ll get nervous.

Because καφέ is the direct object of πίνω, so it is in the accusative singular.

The basic noun is:

• ο καφές = coffee / the coffee

Its accusative singular is:

• τον καφέ

So after πίνω, you get:

• πίνω καφέ = I drink coffee

The word πολύ here matches that accusative singular usage and means a lot of / much:

• πίνω πολύ καφέ = I drink a lot of coffee

By contrast:

• πολύς καφές is nominative, so it would be used as a subject, for example:
• Ο πολύς καφές με κάνει νευρικό.
• A lot of coffee makes me nervous.

Because καφές is the nominative form, and καφέ is the accusative form.

The verb πίνω takes a direct object, and direct objects normally go in the accusative in Greek.

So:

• ο καφές = the coffee
• πίνω τον καφέ = I drink the coffee

Without the article:

• πίνω καφέ = I drink coffee

This is a very common Greek pattern.

Because Greek often leaves out the article with a general, non-specific object, especially with food and drink.

So:

• πίνω καφέ = I drink coffee
• πίνω πολύ καφέ = I drink a lot of coffee

This sounds general, not specific.

If you include the article, it usually sounds more specific:

• πίνω τον καφέ = I’m drinking the coffee / I drink the coffee

That would usually refer to a particular coffee, not coffee in general.

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

The sentence can also be said as:

• Όταν πίνω πολύ καφέ, γίνομαι νευρικός.

This is extremely natural and may even be more common in writing, since the when clause comes first.

The original order:

• Γίνομαι νευρικός όταν πίνω πολύ καφέ.

is also perfectly natural.

The meaning stays the same; the difference is mostly one of emphasis and style.

She would normally change only the adjective:

• Γίνομαι νευρική όταν πίνω πολύ καφέ.

That is because the adjective has to agree with the speaker’s gender.

The rest of the sentence stays the same:

• γίνομαι = I get
• όταν πίνω πολύ καφέ = when I drink a lot of coffee

So the only change is:

• νευρικός → νευρική