Learn Hardcore Greek: Πιστεύω ότι ο χρόνος που βάζω στο μάθημα αξίζει περισσότερο από κάθε άλλο χόμπι. - I believe that the time I put into the lesson is worth more than any other hobby.

ότι (without comma)
- Conjunction = that
- Used after verbs like λέω, πιστεύω, νομίζω, ακούω, ξέρω.
- Example: Ξέρω ότι έχεις δίκιο. – I know that you are right.
πως (no accent)
- Also a conjunction meaning that in many contexts.
- You could say: Πιστεύω πως ο χρόνος… with almost the same meaning.
- Often feels slightly more informal or conversational than ότι.
ό,τι (with a comma)
- Means whatever / anything that.
- Completely different meaning from ότι.
- Example: Κάνε ό,τι θέλεις. – Do whatever you want.

So in this sentence, ότι just introduces the content of what you believe, like English that. You must not use ό,τι here.

Why do we say ο χρόνος with the article, but χόμπι has no article?

Two different reasons:

ο χρόνος
- ο χρόνος που βάζω στο μάθημα = the time that I put into the class.
- The article ο shows we are talking about a specific time: the time you invest in this particular activity.
- Without the article here, χρόνος που βάζω would sound incomplete/odd in this structure.
(κάθε άλλο) χόμπι
- The phrase is κάθε άλλο χόμπι – every/any other hobby.
- With κάθε (every/each), Greek normally does not use an article:
  - κάθε μέρα (every day), κάθε φίλος (every friend), κάθε παιδί (every child).
- So το χόμπι is “the hobby”, but when you say κάθε άλλο χόμπι, the article drops because of κάθε.

So: article with ο χρόνος because of specificity; no article with χόμπι because κάθε blocks it.

What exactly does βάζω mean in ο χρόνος που βάζω στο μάθημα? Why “put” time?

Literally, βάζω means to put (put something somewhere).
In this sentence it is used in a figurative, very common way:

βάζω χρόνο σε κάτι = to put time into something, invest time in something.

It is close to:

αφιερώνω χρόνο – to devote time
ξοδεύω χρόνο – to spend time

So ο χρόνος που βάζω στο μάθημα is naturally understood as:

the time I put into the class / the time I invest in the class.

This figurative use of βάζω with χρόνο/χρήματα/προσπάθεια is very common:

Βάζω πολλή προσπάθεια στη δουλειά μου. – I put a lot of effort into my job.

What is που doing in ο χρόνος που βάζω στο μάθημα? Is it a relative pronoun?

Yes. Here που introduces a relative clause:

ο χρόνος [που βάζω στο μάθημα]
= “the time that I put into the class”

In older or more formal Greek, you could use a more explicit relative pronoun:

ο χρόνος τον οποίο βάζω στο μάθημα

But in modern everyday Greek, που is by far the most common way to introduce such clauses, and it doesn’t change form (it’s invariable):

το παιδί που βλέπω – the child that I see
η ταινία που είδα – the film that I saw
ο χρόνος που βάζω – the time that I put (in)

Why is it στο μάθημα and not σε μάθημα or something like “στην τάξη”?

στο is σε + το, so στο μάθημα literally means in/into the lesson / in the class / in the course.

Nuances:

στο μάθημα
- Refers to a specific class or course you both know about (e.g. your Greek class).
- Greek very often uses a definite article where English might not.
- Common idiomatic expression: Είμαι στο μάθημα = I am in class (attending).
σε μάθημα
- Without the article, it means “in a lesson / in a class (unspecified)”.
- This is possible in some contexts, but sounds odd here, because you clearly mean a particular ongoing course you invest time in.
στην τάξη
- τάξη = classroom / grade (school context).
- στην τάξη is more about the physical classroom or school class as a group.
- στο μάθημα focuses on the lesson/course activity itself.

So στο μάθημα is the natural way to say into the class / into the course in this sentence.

How does the comparative αξίζει περισσότερο από… work in this sentence?

Structure:

αξίζει περισσότερο από X = is worth more than X

Breakdown:

αξίζει – “is worth / has value”.
περισσότερο – “more” (comparative of πολύ).
από – used to introduce the thing you compare with, like “than”.

So:

αξίζει περισσότερο από κάθε άλλο χόμπι
= it is worth more than any other hobby (is worth).

Notes:

After περισσότερο, από is the standard preposition to mean than.
In many comparative sentences, παρά can also be used (often more emphatic or stylistic):
- αξίζει περισσότερο παρά κάθε άλλο χόμπι – also possible.
The second αξίζει (for χόμπι) is understood and omitted:
- Full idea: αξίζει περισσότερο από ό,τι αξίζει κάθε άλλο χόμπι.

Why is it κάθε άλλο χόμπι in the singular, when in English we often say “any other hobbies”?

In Greek, κάθε is singular, but its meaning is universal:

κάθε άλλο χόμπι literally = every other hobby
→ interpreted as any other hobby or “any of the other hobbies”.

Greek uses:

κάθε + singular noun to talk in general about all members of a group:
- κάθε άνθρωπος – every person
- κάθε μέρα – every day
- κάθε άλλο χόμπι – every other hobby / any other hobby

So the singular here is normal and idiomatic. It doesn’t mean there is only one other hobby; it means whichever other hobby you might compare it to.

What gender and case is άλλο in κάθε άλλο χόμπι, and how does agreement work?

In κάθε άλλο χόμπι:

χόμπι is a loanword, neuter, indeclinable (form doesn’t change for case).
After από, we need the accusative case.
So άλλο is neuter singular accusative, agreeing with χόμπι in:
- gender: neuter
- number: singular
- case: accusative (because of από)

Pattern of άλλος (other):

Masculine acc. sg: άλλον (often written άλλο in casual writing when final -ν drops)
Feminine acc. sg: άλλη
Neuter acc. sg: άλλο

Examples:

Βλέπω έναν άλλο φίλο. (masc acc) – I see another (male) friend.
Βλέπω μια άλλη φίλη. (fem acc) – I see another (female) friend.
Βλέπω ένα άλλο παιδί. (neut acc) – I see another child.
από κάθε άλλο χόμπι – than any other hobby.

Is αξίζει here personal (with subject ο χρόνος) or impersonal, like “it is worth it”?

Here αξίζει is personal; its grammatical subject is ο χρόνος (που βάζω στο μάθημα):

(Ο χρόνος …) αξίζει περισσότερο από κάθε άλλο χόμπι.
= The time… is worth more than any other hobby.

There is also an impersonal use of αξίζει, where there is no explicit subject:

Αξίζει. – It’s worth it.
Αξίζει να το δεις. – It’s worth seeing it.

But in your sentence, ο χρόνος is clearly the subject performing the verb αξίζει.

Can we change the word order, for example put αξίζει earlier in the sentence?

Yes, Greek word order is quite flexible. Some natural alternatives:

Original:
- Πιστεύω ότι ο χρόνος που βάζω στο μάθημα αξίζει περισσότερο από κάθε άλλο χόμπι.
Verb earlier:
- Πιστεύω ότι αξίζει περισσότερο ο χρόνος που βάζω στο μάθημα από κάθε άλλο χόμπι.
  (Slight emphasis on αξίζει περισσότερο.)
Emphasis on the comparison part:
- Πιστεύω ότι ο χρόνος που βάζω στο μάθημα αξίζει, περισσότερο από κάθε άλλο χόμπι.
  (With a pause or comma in speech for emphasis.)

All of these are grammatically fine. The original is probably the most neutral and smooth in written style.

Why is the subject “I” not written? Why don’t we say Εγώ πιστεύω?

Greek is a pro-drop language: subject pronouns (εγώ, εσύ, αυτός…) are often omitted because the verb ending already shows the subject.

Πιστεύω ends in -ω, which clearly indicates 1st person singular = “I believe”.

You would use Εγώ πιστεύω mainly when you want to emphasize the contrast:

Εγώ πιστεύω ότι… – I (as opposed to others) believe that…

In your sentence there is no contrast, so Πιστεύω ότι… is the natural form.

Could we replace αξίζει with something like έχει περισσότερη αξία? Would the meaning change?

Yes, you can, and the meaning is basically the same, but αξίζει is more natural and compact.

Possible rephrasing:

Πιστεύω ότι ο χρόνος που βάζω στο μάθημα έχει περισσότερη αξία από κάθε άλλο χόμπι.

This literally means:

I believe that the time I put into the class has more value than any other hobby.

Differences:

αξίζει περισσότερο – very common, idiomatic, slightly more colloquial/natural.
έχει περισσότερη αξία – a bit more formal or explicit (literally “has more value”).

In everyday modern Greek, αξίζει (περισσότερο) is the default way to express “(is) worth (more)”.