Learn Hardcore Turkish: Telefon bir anda kapandı.

It literally means "in one moment," and idiomatically it means "suddenly / all of a sudden." It emphasizes that the action happened abruptly, without warning.

How is "bir anda" different from "aniden," "birden," or "birdenbire"?

All can mean "suddenly," but:

bir anda: very common, neutral register; "in an instant."
aniden: slightly more formal; "suddenly."
birden: "all of a sudden," often for quick changes.
birdenbire / birden bire: more emphatic, "all of a sudden out of nowhere."

What is "anda"? Is the -da here the same as the particle "da/de" meaning "also"?

No. In bir anda, an means "moment" and -da is the locative suffix "in/at/on." So anda = "at the moment." This is not the separate particle de/da ("also/too"), which is written separately and not attached to the word.

Why is "bir" used? Does it really mean "one"?

Here bir functions like English "a" in set phrases; it doesn’t count an actual number. In bir anda, it helps form the idiom meaning "suddenly."

Can I move "bir anda" to a different position?

Yes. All of these are fine, with slight changes in emphasis:

Telefon bir anda kapandı. (neutral)
Bir anda telefon kapandı. (emphasizes the suddenness first)
Telefon kapandı bir anda. (colloquial, end-focus on suddenness)

What does "kapandı" tell us about who did the action?

Kapandı is the intransitive/"middle" form: "shut off/closed (by itself)" or with an unspecified agent. It contrasts with:

kapattı: "someone turned it off."
kapatıldı: "it was turned off" (passive, typically by someone).

How is "kapandı" formed morphologically?

Root: kapa- ("to close")
Intransitive/middle derivation: kapan- ("to close/shut [itself]")
Past tense: -dı (harmonized to last vowel: a → dı)
3rd person singular has no extra ending. So: kapan- + dı → kapandı.

How would different tenses/aspects change the meaning?

kapandı: it shut off (simple past).
kapanıyordu: it was shutting down (past progressive).
kapanmış: it (apparently) shut off / I found out it had shut off (evidential).
kapanacak: it will shut off.
kapanacaktı: it was going to shut off.

How do I negate this or ask a yes/no question?

Negative: Telefon bir anda kapanmadı. ("The phone didn’t shut off suddenly.")
Yes/no: Telefon bir anda kapandı mı? ("Did the phone shut off suddenly?") The question clitic mı/mi/mu/mü follows vowel harmony; here it’s mı.

How do I pronounce the dotless ı in "kapandı"?

Turkish ı is a back, unrounded vowel (like the 'e' in "taken" but further back). Approximate: kah-PAHN-duh. Also, bir anda is spoken smoothly and may sound like "biranda" in fast speech, but it’s written as two words.

Why is there no article like "the" before "telefon"? How do I say "my phone"?

Turkish has no articles. Telefon can mean "the phone" from context. To be specific:

Bu telefon: this phone.
O telefon: that phone.
Telefonum: my phone. So: Telefonum bir anda kapandı.

Is "telefon" the subject? How do we know?

Yes. Turkish subjects are typically unmarked (no case ending) and precede the verb. The verb is 3rd person singular (kapandı), matching the singular subject telefon. The default order is Subject–(Adverbials)–Verb.

How do I say "It shut down by itself" more explicitly?

Add kendiliğinden ("of its own accord"): Telefon kendiliğinden bir anda kapandı. You can drop bir anda if the self-initiated idea is enough: Telefon kendiliğinden kapandı.

What if there are multiple phones? Do I change the verb?

Plural subject: Telefonlar bir anda kapandı. The verb normally stays singular with inanimate plurals. Kapandılar is grammatically possible but sounds odd for objects.

Is "bir an" the same as "bir anda"?

No:

bir anda: "suddenly, all at once."
bir an (için/lığına): "for a moment." Example: Telefon bir anlığına kapandı = "The phone shut off for a moment (then came back)."

Could I say "Telefon söndü" or "Şarjı bitti" instead?

Şarjı bitti: "Its battery ran out" (very common cause).
Telefon söndü: not idiomatic for phones; söndü is for lights/fires. You can say Ekran söndü ("the screen went dark").

What’s the difference between "kapatmak" and "kapamak"?

Both mean "to close/turn off," but kapatmak is the standard modern form, especially for devices. Kapamak is older/literary and less common in everyday speech. The intransitive is kapanmak ("to close/shut [itself]").

Can punctuation change the feel?

Yes. Telefon bir anda kapandı! adds a sense of surprise/urgency. The period is neutral: Telefon bir anda kapandı.