Learn Hardcore Greek: Όταν το σπίτι είναι κενό, έχει τόση ησυχία που συγκεντρώνομαι εύκολα. - When the house is empty, there is so much quiet that I concentrate easily.

Greek uses the present tense after Όταν when talking about a general, repeated situation or habit, just like here: every time the house is empty, it’s quiet and I can concentrate.

Compare:

Όταν το σπίτι είναι κενό, συγκεντρώνομαι εύκολα.
When the house is empty (in general), I can concentrate easily.

For future situations, Greek often still uses the present after όταν, even though English uses the future:

Όταν το σπίτι είναι κενό, θα συγκεντρωθώ εύκολα.
When the house is empty, I will concentrate easily.

So the present είναι after Όταν is normal and expected.

Why do we say το σπίτι with the article το? Could we just say σπίτι?

Greek uses the definite article much more often than English.

το σπίτι = the house (usually a specific, known house – often “my/our house” in context)

In many contexts where English would say “when the house is empty” or even “when home is empty”, Greek still prefers το σπίτι with the article.

You could say όταν σπίτι είναι κενό, but that sounds unnatural and incomplete in standard Greek. Without the article, σπίτι is more like “home” in some set expressions:

πάω σπίτι = I’m going home

Here we are talking about a specific house as a physical place, so το σπίτι with the article is the normal form.

What is the difference between κενό and άδειο for “empty”? Could we say άδειο instead?

Both κενό and άδειο can mean empty, but there are nuances:

άδειο is the most common, everyday word for empty: no people, no objects, no content.
- Το σπίτι είναι άδειο. = The house is empty (no people / no furniture / nothing inside).
κενό is often more neutral or “space-like”: void, space, gap, vacancy, but it can also mean empty in some contexts.

In this sentence, both are grammatically fine:

Όταν το σπίτι είναι κενό...
Όταν το σπίτι είναι άδειο...

Most native speakers would probably say άδειο in everyday speech for “the house is empty (nobody is inside)”.
κενό can sound a bit more neutral/formal or might suggest “devoid of people / activity” rather than literally “empty of furniture”, but the difference is subtle and context-dependent.

Why do we say έχει τόση ησυχία and not something like “είναι ήσυχο”?

Both patterns exist, but they express the idea slightly differently.

είναι ήσυχο = “it is quiet” (describing a state of the house itself)
- Το σπίτι είναι ήσυχο. = The house is quiet.
έχει ησυχία literally = “it has quiet / there is quiet”
- This is a very common Greek way to say “there is quiet / it is quiet around (in terms of atmosphere)”.

By adding τόση:

έχει τόση ησυχία = there is so much quiet / it’s so quiet (emphasizing the degree of quiet)

So:

Όταν το σπίτι είναι κενό, έχει τόση ησυχία που...
When the house is empty, it’s so quiet that...

You could also say:

...είναι τόσο ήσυχο που συγκεντρώνομαι εύκολα.
...it is so quiet that I can concentrate easily.

Both are correct, but έχει ησυχία is very idiomatic Greek.

How does τόση work here, and why is it τόση and not τόσο?

Τόσος / τόση / τόσο is a demonstrative adjective meaning so much / so many / so.

It must agree in gender, number, and case with the noun it modifies:

Masculine: τόσος
Feminine: τόση
Neuter: τόσο

The noun ησυχία (quiet, silence) is:

feminine
singular
nominative

So the correct form is:

τόση ησυχία = so much quiet / so much silence

Examples:

τόσος κόσμος (masc.) = so many people
τόση δουλειά (fem.) = so much work
τόσο φαγητό (neut.) = so much food

What is the function of που in έχει τόση ησυχία που συγκεντρώνομαι εύκολα? Is it a relative pronoun?

Here που is not a relative pronoun (“which / who”).
It introduces a result clause, meaning “that / so that” after an expression of degree (τόση ησυχία).

So:

έχει τόση ησυχία που συγκεντρώνομαι εύκολα
= it is so quiet that I can concentrate easily

Structure:
τόσος/τόση/τόσο + noun + που + clause of result

More examples:

Έχει τόση δουλειά που δεν προλαβαίνει να φάει.
He has so much work that he doesn’t have time to eat.
Είναι τόσο κουρασμένος που κοιμάται όρθιος.
He is so tired that he sleeps standing up.

So here που ≈ that in the phrase “so ... that ...”, not “which/who”.

Why is the verb συγκεντρώνομαι in the middle/passive (reflexive) form and not συγκεντρώνω?

Greek often uses middle/passive forms to express “doing something to/for oneself”, similar to reflexive verbs.

συγκεντρώνω (active) = to gather / to concentrate (something else)
e.g. Συγκεντρώνω πληροφορίες. = I gather information.
συγκεντρώνομαι (middle/passive) = to concentrate (one’s mind), to focus
e.g. Δεν μπορώ να συγκεντρωθώ. = I can’t concentrate.

In this sentence:

συγκεντρώνομαι εύκολα = I can concentrate easily / I focus easily

Using συγκεντρώνω here would be wrong, because you’re not “concentrating something”; you are concentrating yourself, which in Greek is expressed with συγκεντρώνομαι.

What is εύκολα grammatically, and where can it go in the sentence?

Εύκολα is an adverb meaning easily.
It is derived from the adjective εύκολος (easy).

Position in the sentence is relatively flexible. Common placements:

συγκεντρώνομαι εύκολα (most natural here)
εύκολα συγκεντρώνομαι (also possible, slightly different emphasis)

You generally wouldn’t put it far away from the verb it modifies in such a short sentence, so:

που συγκεντρώνομαι εύκολα is the best version here.

In longer sentences, adverbs can move around more, but they still tend to stay close to the verb they describe.

Why is everything in the present tense (είναι, έχει, συγκεντρώνομαι) even though in English we could also say “whenever the house is empty, it’s so quiet that I can concentrate easily”?

In both Greek and English here, the present tense expresses:

a general truth
a habitual / repeated situation

Greek present:

είναι κενό = is empty (whenever that happens)
έχει τόση ησυχία = there is so much quiet (regularly when that condition is met)
συγκεντρώνομαι = I concentrate (habitually, in that situation)

So the present tense is exactly what you’d expect for a general pattern:

Όταν το σπίτι είναι κενό, έχει τόση ησυχία που συγκεντρώνομαι εύκολα.
When(ever) the house is empty, it’s so quiet that I can concentrate easily.

If you were talking about one specific past situation, you’d shift to past tenses:

Όταν το σπίτι ήταν κενό, είχε τόση ησυχία που συγκεντρωνόμουν εύκολα.
When the house was empty, it was so quiet that I could concentrate easily.

Could we change the word order, for example Όταν είναι κενό το σπίτι or move έχει τόση ησυχία?

Yes, Greek word order is fairly flexible, and several variants are natural:

Όταν το σπίτι είναι κενό, έχει τόση ησυχία που συγκεντρώνομαι εύκολα. (original)
Όταν είναι κενό το σπίτι, έχει τόση ησυχία που συγκεντρώνομαι εύκολα.
(slightly different emphasis, but fine)
Όταν το σπίτι είναι κενό, συγκεντρώνομαι εύκολα, γιατί έχει τόση ησυχία.
(now using γιατί = because, changing the structure a bit)

What you usually cannot do is to break apart the τόση ησυχία που chunk or put που somewhere else:

✗ έχει ησυχία τόση που... is possible but less natural here.
✗ συγκεντρώνομαι εύκολα που έχει τόση ησυχία is wrong (reverses cause-result).

So, word order around το σπίτι είναι κενό is flexible; the τόση ησυχία που chunk should stay together as “so much quiet that...”.

Can you explain the grammar of ησυχία? Is it always uncountable like “silence”?

Η ησυχία is a feminine noun, usually uncountable, similar to “quiet / silence” in English.

Basic forms (singular):

Nominative: η ησυχία (subject)
Genitive: της ησυχίας
Accusative: την ησυχία (object)
Vocative: ησυχία (rarely used as a form of address)

It is mostly used in the singular:

Μου αρέσει η ησυχία. = I like quiet.
Θέλω λίγη ησυχία. = I want some quiet.
Δεν έχει καθόλου ησυχία εδώ. = There is no quiet here at all.

So έχει τόση ησυχία literally means “there is so much quiet/silence”, using ησυχία as an uncountable noun.