После длинного совещания все начали зевать, и мне тоже захотелось кофе.

Because после always takes the genitive case in Russian.

• совещание → совещания
• длинное → длинного

So после длинного совещания literally means after a long meeting.

This is a very common pattern:

• после урока — after the lesson
• после работы — after work
• после фильма — after the film

Because Russian adjectives usually agree with the noun they describe in:

• gender
• number
• case

Here, совещание is:

• neuter
• singular
• genitive

So the adjective длинный must also become genitive singular neuter, giving длинного.

That is why the whole phrase is:

• длинное совещание — a long meeting
• после длинного совещания — after a long meeting

Here все means everyone.

Even though the word literally looks like all, in sentences about people it often means everyone:

• Все начали зевать — Everyone started yawning.

The verb is plural because все refers to multiple people.

Compare:

• все люди — all people
• все начали смеяться — everyone started laughing

Because начали зевать means started to yawn or began yawning, not simply yawned.

• зевали = were yawning / yawned
• начали зевать = started yawning

So the sentence emphasizes the beginning of the action. That matches the idea that after the long meeting, people reached the point where they started yawning.

This is a very common Russian pattern:

• начал читать — started reading
• начали говорить — started talking
• начала плакать — started crying

Because the sentence contains two separate clauses:

1. все начали зевать
2. мне тоже захотелось кофе

Each part has its own predicate, so Russian normally uses a comma before и when it links two full clauses.

So this is similar to English:

• Everyone started yawning, and I also felt like having coffee.

Because захотелось is used here in an impersonal construction.

Russian often expresses feelings, urges, and sudden desires with:

• dative person
  • impersonal verb

So:

• мне захотелось кофе = I felt like having coffee / I suddenly wanted coffee

Here мне is the dative case of я.

This pattern is very common:

• мне холодно — I am cold
• мне стало грустно — I became sad
• мне захотелось спать — I felt like sleeping

It is less like I did something, and more like this feeling came to me.

Захотелось is the past-tense form of захотеться, a verb meaning something like:

• to start wanting
• to suddenly feel like

It is related to хотеть (to want), but it has a more sudden or coming-over-you feeling.

So:

• я хочу кофе — I want coffee
• мне захотелось кофе — I suddenly felt like having coffee

The ending -лось shows two things:

1. -сь / -ся: reflexive marker
2. -ло: neuter singular past form, which is common in impersonal expressions

Because the sentence is impersonal: there is no normal grammatical subject like я or он.

In many impersonal Russian past-tense sentences, the verb appears in neuter singular:

• мне повезло — I was lucky
• мне захотелось кофе — I felt like having coffee
• мне не спалось — I couldn’t sleep

So -ло does not mean that something neuter is doing the action. It is just the standard form Russian often uses in impersonal past constructions.

Тоже means also or too.

In this sentence:

• и мне тоже захотелось кофе

the idea is I too felt like having coffee.

Its position helps show that the speaker is included along with everyone else. Russian word order is fairly flexible, but placement affects emphasis.

Here мне тоже strongly suggests:

• me too
• I also

You could move тоже in some cases, but this version sounds natural and clear.

Because кофе is an indeclinable noun in standard Russian. That means its form usually stays the same in different cases.

So you get:

• я люблю кофе
• мне хочется кофе
• после кофе
• без кофе

The form stays кофе.

This word is also traditionally treated as masculine in standard Russian, although in everyday speech learners may hear variation.

Yes. You could say мне хотелось кофе, but it means something slightly different.

• мне захотелось кофе = I suddenly felt like having coffee
• мне хотелось кофе = I wanted coffee / I was in the mood for coffee

So захотелось focuses on the moment the desire appeared, while хотелось sounds more like an ongoing state.

In this sentence, захотелось fits well because it describes a new feeling that came after the meeting.

It is understandable and correct, but many native speakers would more naturally say долгого совещания when talking about something that lasted a long time.

A useful distinction is:

• длинный — long in length; sometimes also long in time
• долгий — long in duration

So:

• длинная дорога — a long road
• долгое совещание — a long meeting

Still, длинного совещания is not impossible. A learner should just know that долгого совещания is often the more idiomatic choice for duration.