Вратарь поймал мяч, и болельщики на трибуне громко закричали.

Because вратарь is a masculine noun of the so-called soft-sign masculine type. In Russian, not all masculine nouns end in a consonant without -ь. Some masculine nouns do end in -ь, especially words for professions or people, for example:

• вратарь — goalkeeper
• учитель — teacher
• словарь — dictionary

So the -ь here does not make the noun feminine. You can tell вратарь is masculine from the word itself and from how it behaves in grammar.

This is about aspect.

• поймал is perfective
• ловил is imperfective

Russian uses the perfective form when the action is seen as completed or as a single finished event. In this sentence, the goalkeeper successfully caught the ball, so поймал is the natural choice.

Compare:

• Вратарь поймал мяч. — The goalkeeper caught the ball.
  (completed result)
• Вратарь ловил мяч. — The goalkeeper was catching / tried to catch the ball.
  (process, repeated action, or no emphasis on the result)

So поймал tells us the catch was successful and complete.

Because мяч is the direct object of поймал (caught what?), so it is in the accusative case.

For this noun, the accusative singular looks the same as the nominative singular:

• nominative: мяч — ball
• accusative: мяч — ball

That happens with many inanimate masculine nouns in Russian. So even though the form does not change, the case is still accusative because of its role in the sentence.

The comma separates two independent clauses:

1. Вратарь поймал мяч
2. болельщики на трибуне громко закричали

Each part has its own subject and verb:

• вратарь
  • поймал
• болельщики
  • закричали

In Russian, when и joins two full clauses like this, a comma is usually needed.

So the structure is:

• The goalkeeper caught the ball, and the fans in the stands shouted loudly.

Because after the consonants г, к, х, ж, ч, ш, щ, Russian normally uses и instead of ы in spelling. This is a standard spelling rule.

The singular is:

• болельщик — fan, supporter

The plural nominative is:

• болельщики — fans

Even though the ending is pronounced somewhat differently from a plain и, it is written -и, not -ы.

Because на here means on / in the stands, indicating location, and with location Russian normally uses the prepositional case.

The noun is:

• трибуна — stand, grandstand, bleachers section

Its prepositional singular is:

• на трибуне — in/on the stands

Compare:

• на трибуне — in the stands (location)
• на трибуну — onto the stand(s) (motion toward)

So in this sentence, the fans are already located there, which is why трибуне is used.

Not necessarily. Russian often uses the singular in places where English might prefer a plural translation.

So на трибуне can often be translated naturally as:

• in the stands
• from the stands

depending on context.

In a stadium context, English usually says the fans in the stands, even though Russian has singular трибуне here. This is a normal difference between the languages.

Громко is an adverb, meaning loudly.

It describes how the fans shouted:

• закричали — shouted / cried out
• громко закричали — shouted loudly

Russian adverbs often end in -о, and they modify verbs:

• быстро — quickly
• тихо — quietly
• громко — loudly

So громко tells us the manner of the shouting.

Again, this is largely about aspect and also about the meaning of the prefix.

• кричали = were shouting / shouted repeatedly
• закричали = started shouting / cried out

The verb закричать often means to begin to shout or to shout out suddenly. In this sentence, after the goalkeeper caught the ball, the fans reacted, so закричали fits very well: it marks the start of the outburst.

Compare:

• болельщики кричали — the fans were shouting
• болельщики закричали — the fans started shouting / shouted out

So закричали gives the sentence a more immediate, event-like feeling.

Because its subject, болельщики, is plural.

Russian past tense verbs agree in number and, in the singular, also in gender:

• закричал — he shouted / started shouting
• закричала — she shouted / started shouting
• закричало — it shouted / started shouting
• закричали — they shouted / started shouting

Since болельщики means fans (plural), the verb must be закричали.

Yes. Russian word order is more flexible than English word order because case endings show grammatical roles.

The neutral order here is:

• Вратарь поймал мяч, и болельщики на трибуне громко закричали.

But other orders are possible, for example:

• Мяч поймал вратарь, и болельщики на трибуне громко закричали.
• Вратарь поймал мяч, и на трибуне болельщики громко закричали.
• Вратарь поймал мяч, и болельщики громко закричали на трибуне.

These versions may sound more marked or emphasize different parts. The original sentence is the most straightforward and natural for simple narration.

They are very close in meaning, but вратарь is the standard native Russian word for goalkeeper. Голкипер is a borrowing from English and is also used, especially in sports contexts, but вратарь is very common and fully standard.

So in a basic sentence like this, вратарь is the most natural choice.

The dictionary forms are:

• поймал → поймать — to catch
• закричали → закричать — to start shouting / to cry out

These are both perfective infinitives.

If you want the imperfective partners, they are usually:

• ловить — to catch, to be catching
• кричать — to shout, to be shouting

This is useful because Russian dictionaries list verbs by their infinitive, not by the past-tense form used in the sentence.