Я не успел допить кофе, потому что началось совещание.

Успел is the past tense of the perfective verb успеть, which means to manage to, to have time to do something.

In this sentence, the speaker is talking about one completed situation in the past: there was a chance to finish the coffee, but that chance ended when the meeting started.

• я не успел = I didn’t manage to
• я не успевал would mean something more like I wasn’t managing to / I didn’t have enough time in a more ongoing or descriptive sense.

So here не успел is the natural choice because it refers to a single finished event.

Also, успел shows that the speaker is male.
A female speaker would say:

• Я не успела допить кофе...

This is a very common Russian pattern.

• успеть + infinitive = to manage to do something in time
• не успеть + infinitive = to not manage to do something in time

So:

• Я не успел допить кофе = I didn’t manage to finish drinking my coffee
• more naturally in English: I didn’t finish my coffee before... or I didn’t have time to finish my coffee

The infinitive tells you what action the person did or didn’t manage to do.

More examples:

• Я успел поесть. = I managed to eat.
• Мы не успели уйти. = We didn’t manage to leave.
• Она успела позвонить. = She managed to call.

Допить means to finish drinking something that was already being drunk.

It comes from:

• пить = to drink
• допить = to drink to the end / finish drinking

So:

• Я не успел пить кофе would sound wrong here, because it means I didn’t manage to drink coffee in a general sense.
• Я не успел допить кофе means I didn’t manage to finish my coffee.

The prefix до- often has the idea of reaching the end or completing something:

• читать = to read

• дочитать = to finish reading

• есть = to eat
• доесть = to finish eating

So допить кофе is exactly the right choice for finish the coffee.

Normally, direct objects in Russian can change form depending on case. But кофе is a special noun: it is usually treated as an indeclinable masculine noun, so its form stays the same.

Here кофе is the direct object of допить, and it remains:

• допить кофе

You do not change it to something else.

A useful thing to remember:

• кофе is traditionally masculine in standard Russian
• but its form does not change across cases in normal usage

So even though it functions as an object, it still looks the same.

Because совещание is a neuter noun.

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

• masculine: начался
• feminine: началась
• neuter: началось
• plural: начались

Since совещание is neuter, the verb must be началось.

Compare:

• начался урок = the lesson started
• началась встреча = the meeting started
• началось совещание = the meeting started
• начались переговоры = the negotiations started

This is an aspect question.

• началось is perfective
• начиналось is imperfective

Here, началось is used because the sentence refers to the meeting’s actual start as a completed event:

• потому что началось совещание = because the meeting started

If you said начиналось, it would suggest something more ongoing, repeated, or descriptive, and it would not fit as well here.

So in this sentence:

• coffee not finished
• then a new event happened: the meeting started

That sudden, completed event calls for началось.

Both are possible, but the word order slightly changes the feel.

• Совещание началось = neutral, straightforward: The meeting started
• Началось совещание = often sounds a bit more event-focused, like then the meeting started or the meeting got underway

In Russian, word order is more flexible than in English. The version in your sentence sounds natural because the clause is giving the reason the speaker could not finish the coffee: the important new event is that the meeting started.

So the sentence could also be:

• Я не успел допить кофе, потому что совещание началось.

This is also correct.

Because потому что means because, and it introduces a subordinate clause.

Russian normally puts a comma before subordinate-clause markers like:

• потому что = because
• когда = when
• если = if
• что = that

So:

• Я не успел допить кофе, потому что началось совещание.

This comma is required in standard writing.

Yes, потому что usually means because and introduces the reason for something.

In this sentence:

• Я не успел допить кофе = what happened
• потому что началось совещание = why it happened

So the structure is:

• [result], потому что [reason]

Very common examples:

• Я ушёл, потому что было поздно. = I left because it was late.
• Она не пришла, потому что заболела. = She didn’t come because she got sick.

It is one of the most basic and useful ways to express cause in Russian.

Yes. In the past tense, Russian verbs often show the gender of the subject.

• Я не успел = the speaker is male
• Я не успела = the speaker is female

This is something English does not do, so it often stands out to learners.

Other forms:

• ты не успел / успела
• он не успел
• она не успела
• мы не успели
• они не успели

So from Я не успел..., we understand that the speaker is male unless the context says otherwise.

Not exactly.

Both can sometimes be translated as meeting, but they are used a bit differently.

• совещание usually means a work meeting, briefing, or conference-style discussion, often more formal or official
• встреча is broader and can mean meeting, appointment, or even encounter

So:

• началось совещание suggests something like an office meeting, planning meeting, staff meeting, etc.
• началась встреча could be a meeting too, but it is less specifically a formal work discussion

In this sentence, совещание fits very naturally.

Yes, you could, but the meaning shifts slightly.

• не успел допить кофе = I didn’t have time to finish my coffee
• не смог допить кофе = I couldn’t finish my coffee

Не успел focuses on time.
Не смог focuses more on ability/circumstances.

Because the second clause says the meeting started, the problem is clearly lack of time, so не успел is the best choice.

Yes. Russian allows several natural word orders.

For example:

• Я не успел допить кофе, потому что началось совещание.
• Потому что началось совещание, я не успел допить кофе.
• Я не успел допить кофе, потому что совещание началось.

All of these are grammatical.

The original version sounds very natural and conversational. It presents:

1. what happened first: I didn’t manage to finish my coffee
2. then the reason: because the meeting started

That order is often the most natural in everyday speech.

Only some parts would change.

Female speaker:

• Я не успела допить кофе, потому что началось совещание.

More than one person:

• Мы не успели допить кофе, потому что началось совещание.

Notice:

• успел → успела → успели
• допить кофе stays the same
• началось совещание stays the same because совещание is still neuter singular

So the first verb changes to match the subject, but the second clause does not.