Едва я зашла в квартиру, как телефон снова зазвонил.

Едва ... как is a common Russian pattern meaning hardly / scarcely ... when.

So the sentence structure is:

• Едва я зашла в квартиру,
• как телефон снова зазвонил.

This creates the idea that the second action happened almost immediately after the first one.

It is similar to English:

• Hardly had I entered the apartment when the phone rang again.
• As soon as I came into the apartment, the phone rang again.

A very close Russian equivalent is как только ... , ... but едва ... как often sounds a bit more literary or emphatic.

Because the speaker or subject я is understood to be female.

In the Russian past tense, verbs agree in gender and number:

• зашёл = masculine
• зашла = feminine
• зашло = neuter
• зашли = plural

So:

• If a man says it: Едва я зашёл в квартиру, как...
• If a woman says it: Едва я зашла в квартиру, как...

This is one of the important differences between Russian and English: past-tense verbs often show the speaker’s gender.

Both зайти and войти can mean to go in / enter, and in many contexts they are close.

Here, зайти в квартиру sounds very natural and idiomatic for to go into the apartment.

A rough distinction:

• войти focuses more directly on entering
• зайти often suggests going in / dropping in / stepping in, and is very common in everyday speech

In this sentence, зашла в квартиру feels conversational and natural.
You could also say:

• Едва я вошла в квартиру, как телефон снова зазвонил.

That would also be correct, though the tone may feel slightly different.

Because this sentence describes motion into the apartment.

In Russian:

• в + accusative = movement into
• в + prepositional = location in / inside

So:

• зашла в квартиру = went into the apartment
• была в квартире = was in the apartment

Compare:

• Я зашла в квартиру. = I went into the apartment.
• Я была в квартире. = I was in the apartment.

This is a very common case pattern to learn.

Because both actions are presented as single completed events.

• зашла = I went in / entered
• зазвонил = began to ring / rang out

Perfective verbs are very common in narratives when you describe one event happening after another.

In this sentence, the idea is:

1. I entered the apartment.
2. Immediately after that, the phone rang.

If you used imperfective forms, the meaning would change or sound less natural here.

For example:

• заходила would suggest repeated action, process, or background context
• звонил means was ringing / used to ring / rang depending on context, but зазвонил specifically highlights the start of the ringing

So the perfective aspect helps tell the story as a sequence of completed events.

Зазвонил is the perfective past of зазвонить, and it usually means started to ring.

That prefix за- often marks the beginning of an action.

So:

• телефон зазвонил = the phone started ringing / rang
• телефон звонил = the phone was ringing / used to ring / rang repeatedly, depending on context

In your sentence, зазвонил is especially good because it marks the sudden event that happened right after entering the apartment.

It gives a stronger sense of:

• suddenness
• a new event beginning
• interruption

No, here как does not mean how.

In the pattern едва ..., как ..., как functions more like when in English:

• Hardly had I entered the apartment, when the phone rang again.

So this is a set construction:

• едва ..., как ...
• только ..., как ...

In other contexts, как can mean:

• how
• as
• like
• part of fixed conjunctions

So you should understand it here as part of the whole pattern, not as a separate literal how.

Yes, it could be omitted, because the verb form already shows the subject:

• зашла already tells you the subject is I and feminine

So both are possible:

• Едва я зашла в квартиру, как телефон снова зазвонил.
• Едва зашла в квартиру, как телефон снова зазвонил.

Including я is completely natural. It can make the sentence a little clearer or slightly more emphatic.

Russian often omits subject pronouns when they are obvious, but it does not have to.

Снова means again.

In many contexts, снова and опять are interchangeable:

• телефон снова зазвонил
• телефон опять зазвонил

Both mean the phone rang again.

A common nuance learners are taught is:

• снова can sound a bit more neutral or literary
• опять can sometimes sound more conversational, and sometimes more like yet again with annoyance

But in real usage, the overlap is large.

So here снова simply tells us the phone had already rung before, and now it rang another time.

Because the sentence contains two clauses:

1. Едва я зашла в квартиру
2. как телефон снова зазвонил

Russian normally separates such clauses with a comma.

The pattern едва ..., как ... requires this punctuation.

So the comma is not optional here.

Not completely, but the given order is the most natural.

Russian word order is flexible, but different orders change emphasis.

The neutral version is:

• Едва я зашла в квартиру, как телефон снова зазвонил.

You could also hear things like:

• Едва я зашла в квартиру, как снова зазвонил телефон.

This shifts the focus slightly toward телефон coming later.

In the original sentence, the order is smooth and standard:

• first clause = entering the apartment
• second clause = the phone rang again

So while Russian allows variation, the original is a very natural default.

It is absolutely understandable and normal, but it can sound a bit more written, narrative, or elevated than the simplest everyday alternatives.

More everyday ways to express a similar idea include:

• Как только я зашла в квартиру, телефон снова зазвонил.
• Только я зашла в квартиру, как телефон снова зазвонил.

Compare the feel:

• едва ... как = slightly more literary or stylistically marked
• как только ... = very common, neutral
• только ... как ... = common and expressive

So yes, natives do use едва, but it is good to recognize that it may sound a little more polished than the most basic spoken option.

Not good English. Even though the Russian structure corresponds to hardly ... when, English usually needs a different grammar pattern.

Natural English options are:

• Hardly had I entered the apartment when the phone rang again.
• As soon as I entered the apartment, the phone rang again.
• I had barely entered the apartment when the phone rang again.

This is useful for learners because Russian and English match in meaning here, but not perfectly in grammar.

Yes. Outside this pattern, едва often means barely / scarcely.

For example:

• Я едва успел. = I barely made it.
• Его было едва видно. = He was barely visible.

In your sentence, though, едва is part of the conjunction-like pattern едва ..., как ..., which means hardly ... when.

So the core idea is still barely / scarcely, but the full structure has a special sentence-level meaning.