Learn Hardcore Greek: Μόλις άνοιξα το φως γιατί ήταν σκοτάδι στο δωμάτιο. - I just turned on the light because it was dark in the room.

“I just turned on the light because it was dark in the room.”
It can also mean “as soon as,” but then we usually expect a second event to follow:
Μόλις άνοιξα το φως, είδα τι είχε γίνει. = “As soon as I turned on the light, I saw what had happened.”
To make the “just now” meaning explicit, you can say μόλις τώρα: Μόλις τώρα άνοιξα το φως.

Why is άνοιξα (aorist) used instead of άνοιγα (imperfect) or έχω ανοίξει (perfect)?

άνοιξα = completed, one-off action in the past (perfective aspect).
άνοιγα = was opening/used to open (ongoing or habitual past) — not appropriate here.
έχω ανοίξει = “I have opened” (result now relevant). With μόλις, Greek prefers the aorist: Μόλις άνοιξα…, not “Μόλις έχω ανοίξει…”.

Is άνοιξα το φως correct, or should it be άναψα το φως?

Both are common and correct.

άναψα το φως (from ανάβω) is the specific verb for turning on a light.
άνοιξα το φως (from ανοίγω) is very common in everyday speech and means “switched on.”
For devices in general, ανοίγω/κλείνω; for lights specifically, ανάβω/σβήνω.

Does Greek really say “open the light”?

Yes. ανοίγω literally means “open,” but colloquially it also means “turn on/switch on” (lights, TV, computer). Similarly, κλείνω means “close/turn off.”

What does γιατί mean here, and how is it different from επειδή or αφού?

Here γιατί = “because.”
επειδή also = “because” (often a bit clearer/neutral, especially sentence-initial).
αφού = “since/seeing that,” often explaining an obvious reason.
All three can introduce reasons, but επειδή avoids confusion with γιατί = “why.”

Could γιατί mean “why” in this sentence?

No, not with the given word order and context. γιατί = “why” typically starts a direct question: Γιατί άνοιξες το φως; = “Why did you turn on the light?”

What does ήταν σκοτάδι literally mean? Are there other ways to say “it was dark”?

Literally “there was darkness.” Other natural options:

Ήταν σκοτεινά (στο δωμάτιο).
Το δωμάτιο ήταν σκοτεινό.
All mean “it was dark.”

Can I say Το δωμάτιο ήταν σκοτεινό instead?

Yes. It’s perfectly natural and a bit more literal: “The room was dark.”

Original: background, impersonal feel (Ήταν σκοτάδι στο δωμάτιο).
Alternative: attributes the property to the room (Το δωμάτιο ήταν σκοτεινό).

What is στο exactly? Why not σε το?

στο is the contracted form of σε + το (“in/at/to the”). Contractions are standard:

σε + το → στο
σε + τα → στα
σε + την → στη(ν)

Why is the article το used with φως? Could I drop it?

Greek typically uses the definite article with concrete nouns in situations like this. Άνοιξα το φως is the normal way to say “I turned on the light.” Dropping the article (άνοιξα φως) sounds wrong here.

Where can μόλις go in the sentence? Is Άνοιξα μόλις το φως okay?

Best placements:

Clause-initial: Μόλις άνοιξα το φως…
After the verb with τώρα: Άνοιξα το φως μόλις τώρα.
Avoid Άνοιξα μόλις το φως, which can sound odd or ambiguous; use μόνο for “only”: Άνοιξα μόνο το φως.

Can I start with the reason clause? For example, Επειδή ήταν σκοτάδι στο δωμάτιο, άνοιξα το φως?

Yes. That’s natural and clear. With sentence-initial “because,” επειδή is preferred over γιατί to avoid confusion with “why.”

What tense is ήταν, and why not είχε σκοτάδι or έπεσε το σκοτάδι?

ήταν is the imperfect of είμαι, used for past states/background: “it was dark.”
είχε σκοτάδι is colloquial/regional; ήταν σκοτάδι or ήταν σκοτεινά are more standard.
έπεσε το σκοτάδι = “night fell” (a different, event-like meaning).

How do I say “turn the light off” in Greek?

Έσβησα το φως (from σβήνω, extinguish/turn off).
Έκλεισα το φως (from κλείνω, close/turn off).
Both are common; σβήνω is the most specific for lights.

What are the forms of φως? How do I say “lights”?

Singular: το φως (genitive: του φωτός).
Plural: τα φώτα.
Examples: Άναψα τα φώτα = “I turned on the lights.”

Pronunciation and stress: anything tricky?

Μόλις: stress on the first syllable.
σκοτάδι: stress on -τά-.
δωμάτιο: stress on -μά-. Remember Greek stress marks show the stressed syllable.

How would I add “my room”?

Say στο δωμάτιό μου. Because δωμάτιο is stressed on the third-from-last, it takes an extra accent before the enclitic μου: δωμάτιο → δωμάτιό μου.