Στο σκοτάδι δεν ξεχωρίζω το μπλε από το μαύρο.

Στο is the contracted form of σε + το.

• σε = in / at / to
• το = the (neuter singular)

So:

• στο σκοτάδι = in the dark

In modern Greek, σε very commonly combines with the article:

• σε + το = στο
• σε + τη(ν) = στη(ν)
• σε + τα = στα

So σε το σκοτάδι would sound unnatural in normal modern Greek.

After σε (and therefore after στο), Greek normally uses the accusative in modern everyday language.

So:

• nominative: το σκοτάδι
• accusative: το σκοτάδι

In this noun, nominative and accusative look the same, so you do not see a visible change.

The whole phrase στο σκοτάδι means in the darkness / in the dark.

Δεν is the normal negation word for verbs in Greek. It means not.

So:

• ξεχωρίζω = I distinguish / I tell apart
• δεν ξεχωρίζω = I do not distinguish / I can’t tell apart

In Greek, δεν usually comes directly before the verb (or before the verb phrase), so its position here is exactly what you would expect.

Here ξεχωρίζω means to distinguish, to tell apart, or to make out the difference between.

In this sentence, it means that the speaker cannot perceive the difference between two colors in the dark.

Depending on context, ξεχωρίζω can also mean things like:

• separate
• stand out
• distinguish

But in ξεχωρίζω το μπλε από το μαύρο, the meaning is clearly tell X from Y.

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

• ξεχωρίζω = I distinguish / I can distinguish

The ending -ω tells you it is first person singular: I.

So Greek usually says:

• δεν ξεχωρίζω = I can’t tell apart

rather than:

• εγώ δεν ξεχωρίζω

The pronoun εγώ would only be added for emphasis, contrast, or clarity.

Here the color words are being used like nouns, not just adjectives.

You can think of them as:

• το μπλε (χρώμα) = the blue (color)
• το μαύρο (χρώμα) = the black (color)

Greek very often uses the definite article with colors when referring to them as color categories.

So:

• το μπλε = blue
• το μαύρο = black

In English we often omit the article in this kind of sentence, but Greek normally keeps it.

Yes, they behave a little differently.

• μαύρο comes from the adjective μαύρος, μαύρη, μαύρο = black
• μπλε is an indeclinable color word (a loanword), so it does not change form

So in this sentence:

• το μαύρο is the neuter singular form, matching an understood noun like χρώμα
• το μπλε stays μπλε because that word normally does not change

That is why the two color words do not look parallel in form, even though they are functioning in the same way.

With ξεχωρίζω, Greek commonly uses the pattern:

• ξεχωρίζω X από Y

This means:

• I distinguish X from Y
• I tell X apart from Y

So:

• ξεχωρίζω το μπλε από το μαύρο = I tell blue from black = I distinguish blue from black

The preposition από here means from.

The order is not crucial to the basic meaning. The sentence still means the speaker cannot distinguish the two colors.

• δεν ξεχωρίζω το μπλε από το μαύρο
• δεν ξεχωρίζω το μαύρο από το μπλε

Both are natural and mean essentially the same thing.

Sometimes the first item is just the one the speaker mentally starts from, or the one being focused on first. But there is no big difference in core meaning here.

Literally, it is I do not distinguish.

But in natural English, the best translation in this context is usually:

• I can’t tell blue from black in the dark.

Greek often uses a simple present negative where English prefers can’t for natural style. So the Greek does not have a separate word for can here, but the idea is understood from context.

Yes. Greek word order is more flexible than English, although some versions sound more neutral than others.

The given sentence:

• Στο σκοτάδι δεν ξεχωρίζω το μπλε από το μαύρο.

is a very natural, neutral sentence.

You could also say:

• Δεν ξεχωρίζω το μπλε από το μαύρο στο σκοτάδι.

That still means the same thing: In the dark, I can’t tell blue from black.

Putting Στο σκοτάδι first gives that setting a little more prominence.

A rough pronunciation guide is:

sto sko-TA-thi den kse-ho-RI-zo to BLE a-PO to MA-vro

A few useful notes:

• σκοτάδι: the δ here is like the th in this
• ξεχωρίζω starts with ξ, pronounced ks
• μπλε is pronounced ble, not like English m-ble
• the stress falls on:
  • σκοτάδι
  • ξεχωρίζω
  • από
  • μαύρο

Yes — it is a very natural Greek way to express this idea.

Useful patterns to remember are:

• στο + noun = in the ...
• δεν + verb = negation
• ξεχωρίζω X από Y = tell X from Y / distinguish X from Y
• το + color = using a color as a noun

So you can build similar sentences, for example:

• Δεν ξεχωρίζω το πράσινο από το μπλε. = I can’t tell green from blue.
• Στο σκοτάδι δεν ξεχωρίζω τα πρόσωπα. = In the dark I can’t make out faces.

This makes the sentence a good model for useful everyday Greek.