Learn Hardcore Russian: Она готовится к экзамену вечером и не хочет говорить по телефону. - She prepares for the exam in the evening and doesn’t want to talk on the phone.

она готовит = she prepares something (a direct object): она готовит ужин – she is making dinner.
она готовится = she is preparing herself (for an exam, competition, trip, etc.): она готовится к экзамену.

You don’t add себя here; the reflexive ending -ся already carries the meaning oneself.

Why do we say к экзамену and not just экзамен or к экзамен?

In Russian, готовиться requires the preposition к + dative case: готовиться к экзамену, к поездке, к свадьбе.

экзамен is nominative (dictionary form).
к экзамену is dative (after к).

So it’s not optional style; it’s a fixed government pattern: готовиться к + dative.

Why к экзамену and not для экзамена?

Both к and для can sometimes translate as for, but they are not interchangeable here.

готовиться к экзамену – to prepare for the exam (directly: you are getting ready to take it).
для экзамена – for the exam in the sense “intended for use in/at the exam”:
материал для экзамена, вопросы для экзамена.

With the verb готовиться, you almost always use к, not для.

Why is the verb in simple present (готовится) when in English we’d say “is preparing”?

Russian doesn’t have a separate present continuous form (is doing). The imperfective present covers both:

она готовится can mean:
- she prepares (as a habit), or
- she is preparing (right now / these days / this evening), depending on context.

So the simple present in Russian often corresponds to English is doing.

What does вечером literally mean, and why not в вечер?

Вечером is the instrumental form of вечер and is used adverbially to mean in the evening / during the evening.

For common times of day, Russian normally uses the instrumental:

утром – in the morning
днём – in the daytime
вечером – in the evening
ночью – at night

Saying в вечер for time (in the evening) is not idiomatic; you say вечером.

Does вечером apply only to “готовится” or also to “не хочет говорить по телефону”?

Formally, the sentence is a bit ambiguous, because вечером is placed right after к экзамену and before и:

Most natural reading: вечером refers to готовится к экзамену (she prepares in the evening).
But in context, it can also be understood more broadly: this evening she’s preparing for the exam and therefore doesn’t want to talk on the phone.

If you want to make it clearly apply to both actions, you could say:
Вечером она готовится к экзамену и не хочет говорить по телефону.
Now вечером clearly sets the time frame for the whole sentence.

Why is it не хочет говорить, not не хочет, чтобы говорила or something similar?

Russian often uses хотеть + infinitive:

она хочет говорить – she wants to talk
она не хочет говорить – she doesn’t want to talk

You only use a чтобы + past tense clause when the “wanting” is about someone else’s action:

Она не хочет, чтобы он звонил. – She doesn’t want him to call.

Here she herself is the one who would talk, so не хочет говорить is the natural form.

Why is the не before хочет instead of before говорить? Would она хочет не говорить по телефону be OK?

Word order of не changes the meaning:

она не хочет говорить по телефону – she does not want to talk on the phone (neutral negation of wanting).
она хочет не говорить по телефону – she wants not to talk on the phone (a contrastive meaning: e.g. she wants to text, not talk).

In your sentence you want the neutral “she doesn’t want to…”, so не goes with хочет.

Why is говорить used here and not сказать or поговорить?

These verbs are close but not the same:

говорить (imperfective) – to speak / to talk in general or over some time.
не хочет говорить по телефону – she doesn’t want to be talking on the phone.
сказать (perfective) – to say / tell (a single finished act, usually a specific message).
она не хочет ничего сказать – she doesn’t want to say anything.
поговорить (perfective) – to have a (short) talk, a conversation.
она не хочет поговорить по телефону – she doesn’t want to (have) a talk on the phone (once).

For a general refusal to be on the phone, говорить по телефону is the most natural.

Why is it говорить по телефону and not на телефоне or с телефоном?

Russian uses по + dative for communication channels:

говорить по телефону – talk on the phone
говорить по радио – speak on the radio
передача по телевизору – a program on TV
созваниваться по скайпу – call each other via Skype

на телефоне is colloquial and usually means on (using) the phone in a more physical/technical sense (e.g. apps on your phone), not “talk on the phone” as an action.
с телефоном = with a phone (physically with you), not “on the phone” (talking).

What case is телефону in, and why that case?

Телефону is dative singular, required by the preposition по in this usage:

по телефону (dative) – by phone / on the phone.

Different prepositions demand different cases. Here по + dative expresses the medium or channel of communication.

Can the word order be changed, for example: Она вечером готовится к экзамену и не хочет говорить по телефону?

Yes. Russian word order is fairly flexible.

Она готовится к экзамену вечером… – neutral, slightly emphasizing готовится к экзамену as the main fact, and then telling when.
Она вечером готовится к экзамену… – slightly stronger emphasis on вечером, setting the time at the start.

Both are grammatically correct; the differences are subtle and mostly about emphasis and rhythm.

Why is она included? Could we omit the pronoun like in Spanish?

In Russian, the subject pronoun can be omitted when the subject is very clear from context, especially in the 1st and 2nd person:

Готовлюсь к экзамену. – I’m preparing for the exam.

But with 3rd person (он/она/они), Russian usually keeps the pronoun, especially in written or neutral speech, to avoid ambiguity:

Она готовится к экзамену… is the normal, natural version.
Omitting она (Готовится к экзамену…) would need a strong context where it’s absolutely clear who is being talked about.