Learn Hardcore Russian: Вчера на вечеринке я был фотографом, а завтра буду переводчиком. - Yesterday at the party I was the photographer, and tomorrow I will be a translator.

In the present, you usually omit the verb to be:
- Я фотограф. – I am a photographer. (no verb)
In the past and future, you must use быть:
- Я был фотографом. – I was a photographer.
- Я буду переводчиком. – I will be a translator/interpreter.

So in this sentence we need был and буду to show past and future.

How would this sentence change if the speaker were female?

Only the past tense form of быть has to agree in gender:

Masculine: я был фотографом
Feminine: я была фотографом

For переводчик, there are two options for a woman:

Use the masculine profession word (very common in real life):
- Я была фотографом, а завтра буду переводчиком.
  (Many women say it exactly like this.)
Use an explicitly feminine form for “translator”:
- Я была фотографом, а завтра буду переводчицей.

Фотограф also has a feminine form (фотографка), but it is much less common and can sound stylistically marked, so фотографом is the usual choice for both genders.

Can I omit я and say Вчера на вечеринке был фотографом, а завтра буду переводчиком?

It is grammatically possible, but not very natural in this exact sentence.

Был фотографом without я can sound like “there was a photographer” or “he was a photographer”, depending on context.
Буду переводчиком without я is easier to understand as “I will be a translator,” but it’s still more neutral to keep я.

In most normal contexts you would say:

Вчера на вечеринке я был фотографом, а завтра буду переводчиком.

Dropping я here risks ambiguity, especially in the first clause.

Why is it на вечеринке and not в вечеринке?

With events in Russian (party, concert, lecture, meeting, exam, etc.), you almost always use на to mean “at”:

на вечеринке – at the party
на концерте – at the concert
на лекции – at the lecture

So в вечеринке is wrong in this meaning.

Also, на + вечеринке uses the prepositional case:

вечеринка (nominative) → на вечеринке (prepositional: где? – where?).

Why is there a comma and а in the middle? Why not just и?

The conjunctions:

и = and, just adds information.
а = often “and” with contrast / “whereas, but”.

The sentence contrasts:

Yesterday – я был фотографом
Tomorrow – я буду переводчиком

So а is used to show this contrast between two different roles at two different times:

…я был фотографом, а завтра буду переводчиком.
→ “…I was the photographer, but/whereas tomorrow I will be the interpreter.”

Using и would sound less natural here and would not highlight the contrast as clearly.

How do we form the future буду переводчиком? Is буду like “will be”?

Yes, буду is “I will be”, the 1st person singular future of быть.

The full future paradigm of быть is:

я буду – I will be
ты будешь – you (sg.) will be
он / она / оно будет – he / she / it will be
мы будем – we will be
вы будете – you (pl./formal) will be
они будут – they will be

So:

я буду переводчиком = I will be (as) a translator/interpreter.

Could we say Завтра стану переводчиком instead of завтра буду переводчиком? What is the difference?

You can say both, but the meaning is different:

буду переводчиком – I will be (serve as) a translator/interpreter at that time.
- Neutral description of a role or state.
стану переводчиком – I will become a translator.
- Implies a change of profession / new status.

In this sentence, the idea is that tomorrow, at some event or in some situation, the speaker’s role will be translator (not that they are changing their career). So буду переводчиком is more appropriate.

What is the word order rule here? Could I say Я был фотографом вчера на вечеринке?

Russian word order is flexible, but there are neutral patterns.

The original:

Вчера на вечеринке я был фотографом…

puts time (вчера) and place (на вечеринке) first, which is a very natural order: time → place → subject → verb → complement.

You can say:

Я был фотографом вчера на вечеринке.

This is grammatically correct, but:

starting with вчера на вечеринке feels more natural and focused:
- first you set the scene (when/where),
- then you say who and in what role.

So both are possible, but the original word order is the more typical neutral choice here.

How would you say a similar sentence in the present: “Today at the party I am the photographer”?

In the present, Russian normally drops the verb быть and uses the nominative for professions:

Сегодня на вечеринке я фотограф. – Today at the party I am the photographer.

Compare:

Present: я фотограф (nominative, no verb).
Past/future: я был / буду фотографом (instrumental with быть).

So you change both the case (фотограф → фотографом) and the presence of быть when you switch between present and past/future.

Why is it вечеринке and not just вечеринка?

Because вечеринке is the prepositional case form, used after на when talking about location:

Что? (nominative) – вечеринка – a party
Где? (prepositional) – на вечеринке – at the party

For most feminine nouns in -а, the prepositional singular is -е:

школа → в школе
работа → на работе
вечеринка → на вечеринке

How do we know if this means “a photographer / a translator” or “the photographer / the translator,” since Russian has no articles?

Russian does not have articles, so definiteness (“a” vs “the”) is understood from context and situation.

The phrase:

я был фотографом

can be translated as:

“I was a photographer”
or “I was the photographer”

Depending on what makes sense in the context.

At a party, there is usually one specific person whose role is “the photographer,” so in natural English many people would say:

“Yesterday at the party I was the photographer, and tomorrow I’ll be the interpreter.”

But grammatically, the Russian sentence itself does not force a or the; it’s neutral, and the translator chooses based on context.

Does переводчик mean “translator” or “interpreter”?

Переводчик can mean both in general:

translator (written texts)
interpreter (spoken language)

If you need to be precise, you can say:

письменный переводчик – translator (written)
устный переводчик – interpreter (spoken)
синхронный переводчик / переводчик-синхронист – simultaneous interpreter

In everyday speech, context usually tells you which one is meant. In this sentence (talking about roles at events), it is very natural to understand переводчик as interpreter.

Can I say Вчера на вечеринке я фотографировал instead of я был фотографом? What is the difference?

You can, but it changes the nuance:

я был фотографом – I was the photographer (that was my role / position).
я фотографировал – I was taking photos / I was photographing (describes what I was doing, not my role).

So:

If you want to say that at the party you had the job/role of the photographer, use я был фотографом.
If you just want to say you took photos, without focusing on being the photographer, use я фотографировал.

How are the words in this sentence stressed: вчера, вечеринке, фотографом, переводчиком?

The main stresses are:

вчера́ – vcherá (stress on -ра́)
вечери́нке – vecherínke (stress on -ри́н-)
фото́графом – fotógrafom (stress on -то́-)
перево́дчиком – perevódchikom (stress on -во́д-)

Unstressed о and е are reduced in pronunciation, especially in fast speech, but the stressed syllables above stay clear and strong.