Learn Hardcore Russian: Мой брат работает программистом, а моя сестра хочет быть переводчицей. - My brother works as a programmer, and my sister wants to be a translator.

Because Russian normally uses the instrumental case for professions after verbs like быть (to be), стать (to become), and often работать (to work).

программист is nominative (dictionary form).
программистом is instrumental singular (masculine/neuter: -ом).

In this sentence, работать кем? чем? (to work as who/what?) requires the instrumental:

Он работает врачом. – He works as a doctor.
Она работает учительницей. – She works as a (female) teacher.

So Мой брат работает программистом literally means “My brother works as a programmer.”

What’s the difference between Мой брат программист and Мой брат работает программистом?

Both can be translated as “My brother is a programmer,” but they have different nuances.

Мой брат программист.
- No verb in Russian (present “to be” is usually omitted).
- Simple statement of identity/occupation, more static:
  - “My brother is a programmer (that’s his profession).”
Мой брат работает программистом.
- Uses the verb работает (works).
- Focuses more on what he does for work, his current employment:
  - “My brother works as a programmer (that’s his job right now).”

In many everyday contexts they’re interchangeable, but работает программистом feels a bit more like “this is his job,” while мой брат программист is more like “this is what he is by profession.”

Why doesn’t Russian use a present-tense form of “to be” here, like есть?

In standard modern Russian, the verb быть (“to be”) is normally omitted in the present tense in simple “X is Y” sentences.

So instead of:

✗ Мой брат есть программист.

You say:

Мой брат программист. – My brother is a programmer.

When you see есть in such a sentence, it usually has a special meaning (emphasis, contrast, or older/very formal style), or it means “to exist/have” rather than just “is.” In this sentence Russian uses работает программистом, so the meaning of “is” is already built into работает (“works [as]”). No extra “to be” is needed.

Why is it моя сестра but мой брат? Why do мой / моя change?

Мой / моя / моё / мои are gender- and number-dependent forms of “my” and must agree with the noun they modify.

брат (brother) is masculine → мой брат
сестра (sister) is feminine → моя сестра
окно (window) is neuter → моё окно
друзья (friends) is plural → мои друзья

So:

Мой брат работает…
А моя сестра хочет…

The change from мой to моя is just grammatical agreement with masculine vs feminine nouns.

What does the conjunction а mean here, and how is it different from и?

Both а and и can often be translated as “and”, but they have different functions:

и = simple addition:
- Мой брат работает программистом, и моя сестра учится.
- “My brother works as a programmer, and my sister studies.”
а = contrast or comparison between two things:
- Мой брат работает программистом, а моя сестра хочет быть переводчицей.
- Implies: “My brother works as a programmer, whereas my sister wants to be a translator.”

So а here contrasts the brother’s current job with the sister’s (different) aspiration.

Why is it переводчицей and not переводчик or переводчиком?

Several things are happening at once:

Profession word:
- переводчик = translator (usually masculine or generic).
- The feminine form is переводчица (female translator).
Case:
- After быть
  - profession, Russian uses the instrumental case:
    - быть кем? чем? – “to be who/what?”
- Feminine instrumental singular of переводчица is переводчицей.
In the sentence:
- хочет быть переводчицей = “wants to be a (female) translator.”
- переводчицей is therefore:
  - feminine
  - singular
  - instrumental case

If you used a generic masculine form, you’d get хочет быть переводчиком, but since the subject is сестра (female), переводчицей is the natural, explicitly feminine form.

Why is it хочет быть переводчицей and not just хочет переводчицей?

In Russian, “want to be X” is normally expressed as:

хотеть + быть + (profession in instrumental)

So:

Она хочет быть переводчицей. – She wants to be a translator.
Он хочет быть врачом. – He wants to be a doctor.

You cannot drop быть here:

✗ Она хочет переводчицей. – ungrammatical.

Dropping быть works only in present-tense “X is Y” statements (Мой брат программист), not after хотеть in this sense.

Why are программистом and переводчицей in different forms if both are professions?

They’re different because they:

Belong to different gender and declension types, and
Still both use the instrumental case.

программист (masculine, hard-stem):
- Instrumental singular → программистом (-ом ending).
переводчица (feminine, -а ending):
- Instrumental singular → переводчицей (-цей / -ицей ending).

So the function is the same (instrumental → “as a programmer,” “as a translator”), but the forms differ because the underlying nouns are of different grammatical types.

Is repeating мой / моя necessary? Could you say just Мой брат работает программистом, а сестра хочет быть переводчицей?

You can omit the second possessive and say:

Мой брат работает программистом, а сестра хочет быть переводчицей.

This is still correct and natural. However:

Repeating моя makes it extra clear that we are talking about “my sister”, not just some sister in general.
In spoken Russian, both versions are used. Repetition often sounds a bit more emphatic or careful:
- “My brother works as a programmer, and my sister wants to be a translator.”

So it’s not required, but it’s perfectly normal and doesn’t sound redundant.

Can the word order be changed, for example Программистом работает мой брат?

Yes, Russian word order is relatively flexible, and you can say:

Программистом работает мой брат, а переводчицей хочет быть моя сестра.

This is grammatically correct, but:

The original (Мой брат работает программистом…) is the most neutral and common order: Subject – Verb – Complement.
Fronting программистом or переводчицей can give them more emphasis (e.g., focusing on the job rather than the person):
- Программистом работает мой брат – “It’s my brother who works as a programmer,” with a slight focus on “as a programmer.”

For a learner, the original word order is the best to imitate until you’re comfortable with Russian emphasis patterns.

How do you pronounce and stress the tricky words работает and переводчицей?

работает (works)
- Syllables: ра-бо-та-ет
- Stress: рабо́тает – stress on the second syllable -бо-.
- Approximate: ra-BO-ta-yet.
переводчицей (as a female translator – instrumental)
- Base: перево́дчик (translator) → feminine перево́дчица → instrumental перево́дчицей.
- Syllables: пе-ре-во-дчи-цей
- Stress: перево́дчицей – stress on во́.
- Approximate: pe-re-VOCH-tsi-y.

Getting the stress right is important; moving the stress can make the word sound odd or even like a different word.