Bar gece çok kalabalıktı.

kalabalıktı = kalabalık + -tı

• kalabalık = crowded
• -tı = past form of to be

So kalabalıktı means was crowded.

Turkish often attaches the idea of was/is directly to a noun or adjective instead of using a separate word.

Because Turkish usually does not use a separate verb like English to be in sentences with nouns and adjectives.

Compare:

• Bar çok kalabalık. = The bar is very crowded.
• Bar çok kalabalıktı. = The bar was very crowded.

In the present tense, the copula is often invisible.
In the past tense, it appears as an ending like -tı / -di / -du / -dü.

This is because of consonant harmony.

The word kalabalık ends in k, which is a voiceless consonant, so the past copula takes the t form rather than d.

That is why you get:

• kalabalık + tı → kalabalıktı

The vowel ı is chosen by vowel harmony.

gece literally means night, but in this sentence it works as a time expression.

Depending on context, it can mean:

• at night
• that night

Turkish often uses simple time words this way without a preposition.

Because Turkish often uses bare time words to answer when?

For example:

• bugün = today
• yarın = tomorrow
• gece = at night / that night

So gece here is acting like an adverb of time.

gecede would not be the normal form here. It would sound more like in the night, which is not what this sentence is trying to say.

Turkish does not have articles like English the or a/an.

So bar can mean:

• the bar
• a bar

The exact meaning depends on context. In many simple translations, English uses the bar because it sounds most natural.

Because çok means very here, and in Turkish, words like very normally come before the adjective or adverb they modify.

So:

• çok kalabalık = very crowded
• çok kalabalıktı = was very crowded

Not completely. Turkish word order is more flexible than English, although the predicate usually comes at the end.

This sentence follows a common pattern:

• Bar = subject
• gece = time expression
• çok = degree word
• kalabalıktı = predicate

You could also hear:

• Gece bar çok kalabalıktı.

That puts more focus on gece. The meaning stays basically the same, but the emphasis changes.

You could, but it means something slightly different.

• Bar çok kalabalıktı = The bar was very crowded.
• Bar çok kalabalık oldu = The bar became/got very crowded.

So in your sentence, kalabalıktı is the better choice if you are simply describing a past situation.

By itself, gece usually means at night, or sometimes that night if the context is clear.

If you specifically want:

• tonight → bu gece
• that night → o gece

So gece alone is possible, but bu gece or o gece can be clearer when needed.