Learn Hardcore Greek: Όταν αναπνέεις βαθιά, το σώμα ηρεμεί. - When you breathe deeply, the body calms down.

Όταν introduces a time clause (a dependent clause).
It is usually followed by a verb in the present or past tense, depending on the meaning:
- Όταν αναπνέεις βαθιά, το σώμα ηρεμεί.
  Whenever you breathe deeply, the body calms down. (general truth)
- Όταν ήρθες, κοιμόμουν.
  When you came, I was sleeping. (specific past situation)

Contrast with αν:

αν = if (condition)
όταν = when / whenever (time)

Sometimes in English both can translate as if, but in Greek the difference is kept clear.

Why is there no word for you before αναπνέεις?

Greek usually leaves out subject pronouns because the verb ending already shows who the subject is.

Verb: αναπνέεις
- stem: αναπν- (αναπνέω = to breathe)
- ending: -εις = you (singular)

So:

(Εσύ) αναπνέεις = You breathe

The εσύ (you) is normally dropped unless you want to emphasize it:

Όταν εσύ αναπνέεις βαθιά, το σώμα ηρεμεί.
When you (specifically) breathe deeply, the body calms down.

In the original sentence, you is understood from αναπνέεις, so it is not written.

What exactly does αναπνέεις mean, and what form is it?

αναπνέεις is:

the present tense
active voice
2nd person singular form of the verb αναπνέω = to breathe

So it means you breathe or you are breathing.

Greek present tense covers both:

Όταν αναπνέεις βαθιά
= When you breathe deeply
= When you are breathing deeply

The choice between simple and continuous in English (breathe / are breathing) is context-dependent; in Greek, the same form is used here.

What does βαθιά mean, and why does it end in -ά?

βαθιά here means deeply.

It comes from the adjective βαθύς (deep) and is used as an adverb in this sentence.

βαθύς = deep (masculine adjective)
βαθιά (or βαθειά in older spelling) = deeply (adverb)

So:

αναπνέω = I breathe
αναπνέω βαθιά = I breathe deeply

Greek often forms adverbs from adjectives with an ending in -α, especially from adjectives like:

βαθύς → βαθιά (deep → deeply)
γλυκός → γλυκά (sweet → sweetly)
κακός → κακά (bad → badly / badly-behaved)

So βαθιά here modifies αναπνέεις (how you breathe).

Why is there a comma after βαθιά?

The comma separates two clauses:

Όταν αναπνέεις βαθιά – the dependent time clause (when you breathe deeply)
το σώμα ηρεμεί – the main clause (the body calms down)

In Greek, just like in English, when a dependent clause comes before the main clause, it is normally followed by a comma:

Όταν αναπνέεις βαθιά, το σώμα ηρεμεί.
Το σώμα ηρεμεί όταν αναπνέεις βαθιά. (no comma needed here)

So the comma is there for the same reason as in English.

Why is it το σώμα and not something like ένα σώμα or σώμα without an article?

το σώμα literally is the body (with the definite article το).

In Greek, the definite article is often used where English uses:

the definite article (the)
a possessive (your)
or no article at all in a general statement.

Here, το σώμα means the body in a general sense: the human body, your body, people’s bodies in general.

So:

Όταν αναπνέεις βαθιά, το σώμα ηρεμεί.
≈ When you breathe deeply, your body calms down.
≈ When you breathe deeply, the body (in general) calms down.

Using ένα σώμα (a body) would sound strange; it would suggest just some random body, not your own.
Leaving the article out (σώμα ηρεμεί) is ungrammatical in standard Greek in this position.

Why is the article το used with σώμα?

το is the neuter singular definite article in the nominative case.

The noun σώμα (body) is:

neuter
singular
nominative (subject of the sentence)

So:

το σώμα = the body (subject)
του σώματος = of the body (genitive)
το σώμα (again) = the body (object – accusative; same form as nominative in neuter)

Many neuter nouns ending in -μα follow this pattern:

το σώμα – the body
το πράγμα – the thing
το γράμμα – the letter

Here το σώμα is the subject, so nominative το is used.

What does ηρεμεί mean, and how is it different from είναι ήρεμο?

ηρεμεί is:

present tense
3rd person singular of ηρεμώ = to calm down / to become calm (intransitive) or to calm (transitive)

So το σώμα ηρεμεί means the body calms down or the body becomes calm.

Difference from είναι ήρεμο:

το σώμα ηρεμεί
focuses on the process / change: the body goes from not calm → calm.
το σώμα είναι ήρεμο
describes a state: the body is calm (already calm).

In this sentence, the idea is that as you breathe deeply, the body is in the process of calming down, so ηρεμεί fits better.

Can ηρεμεί also mean calms (something), like it calms the body?

Yes, ηρεμώ can be:

intransitive: someone/something becomes calm
- Το σώμα ηρεμεί. – The body calms down.
transitive: someone/something calms someone else
- Η μουσική ηρεμεί το σώμα. – The music calms the body.

In your sentence, το σώμα is the subject, so ηρεμεί is clearly used intransitively:
the body is the thing that becomes calm, not something that calms something else.

Could I change the word order to Το σώμα ηρεμεί όταν αναπνέεις βαθιά?

Yes, that is perfectly correct Greek:

Το σώμα ηρεμεί όταν αναπνέεις βαθιά.

Both orders are fine:

Όταν αναπνέεις βαθιά, το σώμα ηρεμεί.
Το σώμα ηρεμεί όταν αναπνέεις βαθιά.

The difference is mainly emphasis:

Starting with Όταν αναπνέεις βαθιά emphasizes the condition / time.
Starting with Το σώμα ηρεμεί emphasizes the result / effect.

Grammatically, both are natural.

Why is Όταν capitalized, and do these words always have accents like this?

Όταν is capitalized simply because it is the first word of the sentence. In the middle of a sentence it would be όταν.

As for the accents:

αναπνέεις
βαθιά
σώμα
ηρεμεί

Modern Greek uses a single accent mark to show the stressed syllable of most words with more than one syllable. These accents:

are part of normal spelling
show you where to put the stress when you pronounce the word:
- α-να-ΠΝΕ-εις → αναπνέεις
- βα-ΘΙΆ → βαθιά
- ΣΏ-μα → σώμα
- η-ρε-ΜΕΊ → ηρεμεί

So the accents are not optional; they are required in correct written Greek.