Όταν η οθόνη του κινητού είναι σπασμένη, δεν βλέπω καλά τα μηνύματα.

Both όταν and αν can be translated as “when / if”, but they are not interchangeable:

• όταν = whenever / when(ever), used for situations that are:

  • repeated, habitual, or generally true
  • or clearly expected to happen at some point

• αν = if, used for:

  • real or hypothetical conditions
  • things that may or may not happen

In this sentence:

Όταν η οθόνη του κινητού είναι σπασμένη, δεν βλέπω καλά τα μηνύματα.
When the phone screen is broken, I don’t see the messages well.

The speaker is talking about a general situation: whenever the screen is broken, the result is always that they can’t see the messages well. That’s why όταν is more natural.

If you used αν here (Αν η οθόνη του κινητού είναι σπασμένη…), it would sound more like a hypothetical “If the screen happens to be broken…”—possible, but a bit different in feeling.

You must use the article here. In Greek, nouns almost always take an article in cases like this.

• η οθόνη = the screen

Unlike English, Greek uses the definite article:

• with specific things: η οθόνη του κινητού = the phone’s screen
• with body parts, family members, etc.
• very often where English might drop the or use no article.

Όταν οθόνη του κινητού… is ungrammatical. You need:

• Όταν η οθόνη του κινητού είναι σπασμένη…

του κινητού is the genitive case of το κινητό (the mobile phone / cell phone).

• το κινητό = the mobile phone (nominative)
• του κινητού = of the mobile phone (genitive)

We use the genitive case to show possession or “of”:

• η οθόνη του κινητού = the screen of the mobile (phone) / the mobile phone’s screen

So the structure is:

• η οθόνη (the screen)
• του κινητού (of the mobile phone)

Literally: “the screen of-the-mobile”.

The adjective must agree in gender, number, and case with the noun it describes.

• η οθόνη is:
  • feminine
  • singular
  • nominative

The adjective σπασμένος (“broken”) has these main singular forms:

• σπασμένος (masculine)
• σπασμένη (feminine)
• σπασμένο (neuter)

Since οθόνη is feminine, we must use the feminine form:

• η οθόνη είναι σπασμένη
  the screen is broken

είναι σπασμένο (neuter) would be correct with a neuter noun, e.g.:

• το τζάμι είναι σπασμένο = the glass is broken.

σπασμένη here functions as an adjective meaning “broken”, derived from the verb σπάζω / σπάω (“to break”).

• είναι σπασμένη = is broken (state / condition)
• έσπασε = broke (event, past action)

So:

• Η οθόνη του κινητού είναι σπασμένη.
  Focus on the current state of the screen: it is in a broken condition.

• Η οθόνη του κινητού έσπασε.
  Focus on the event: the screen broke (at some point in the past).

In this sentence, we care about the situation when the screen is in a broken state, so είναι σπασμένη is the natural choice.

Yes, Greek allows relatively flexible word order. Both are grammatically correct:

• δεν βλέπω καλά τα μηνύματα
• δεν βλέπω τα μηνύματα καλά

They both mean roughly: “I don’t see the messages well.”

Nuance (very slight and context‑dependent):

• δεν βλέπω καλά τα μηνύματα
  Slight emphasis on how well you see (the manner: καλά) before introducing the object (τα μηνύματα).

• δεν βλέπω τα μηνύματα καλά
  Slight emphasis on the messages first, then you add that you don’t see them well.

In everyday speech, both are fine; the original order is very natural.

καλά here is an adverb, meaning “well”.

• καλός / καλή / καλό are adjective forms = good (describing a noun)
• καλά (as an adverb) = well (describing how you do something)

In the sentence:

• δεν βλέπω καλά τα μηνύματα
  • βλέπω = I see
  • καλά modifies the verb βλέπω → see well

If you used καλός / καλή / καλό, you would be describing a noun, not how you see. For example:

• καλό μήνυμα = good message (adjective + noun)

Both are possible, but they feel different:

• τα μηνύματα = the messages (more specific or known)
• μηνύματα = messages (more general, less specific)

In everyday speech, when you talk about your phone messages (SMS, app messages, etc.), Greeks naturally use the article:

• Δεν βλέπω καλά τα μηνύματα.
  → “I don’t see the (my/these) messages well.”

Saying Δεν βλέπω καλά μηνύματα. is grammatically possible, but it sounds more like:

• “I don’t (ever) see messages well” / “I don’t see messages well (in general).”

So with phones, τα μηνύματα is the natural, idiomatic choice.

• η οθόνη (the screen)

  • Gender: feminine
  • Singular: η οθόνη
  • Plural: οι οθόνες

• το μήνυμα (the message)

  • Gender: neuter
  • Singular: το μήνυμα
  • Plural: τα μηνύματα

In the sentence:

• η οθόνη του κινητού → singular (one screen)
• τα μηνύματα → plural (multiple messages)

το κινητό is short for το κινητό τηλέφωνο = the mobile phone / cell phone.

In everyday modern Greek:

• το κινητό alone is completely normal and is usually understood as “mobile phone”.
• If you say το τηλέφωνο, context will decide if it’s a landline or a mobile.
• το κινητό τηλέφωνο is more formal / explicit, but people rarely need the full expression in casual speech.

So η οθόνη του κινητού is naturally understood as “the screen of the mobile (phone)”.

Greek present tense is widely used for:

• general truths
• habitual situations
• whenever-conditions with όταν

So:

• Όταν η οθόνη του κινητού είναι σπασμένη, δεν βλέπω καλά τα μηνύματα.

is a general rule: whenever that condition is true (screen broken), the result follows (can’t see messages well).

You could add μπορώ to mirror English “can’t”:

• … δεν μπορώ να δω καλά τα μηνύματα.

But it’s not necessary; δεν βλέπω καλά τα μηνύματα already implies “I’m not able to see the messages well” in this context. The plain present is the normal way to express this kind of general situation in Greek.