Eğlence gece başladı.

Because Turkish usually puts the finite verb at the end.

So the basic structure here is:

• Eğlence = the subject
• gece = a time expression
• başladı = the verb, started / began

That makes Eğlence gece başladı a normal Turkish word order.

No. The subject is eğlence.

Here, gece is a time word meaning something like at night or during the night, depending on context.

So:

• eğlence = the fun / entertainment / party
• gece = at night
• başladı = started

In Turkish, time words can often appear without a preposition.

Because Turkish often uses bare time words as adverbs.

So gece can mean:

• at night
• during the night

You do not always need a locative ending for time expressions.

Compare the idea in English:

• we say this morning, not in this morning

Turkish often does something similar with time words.

Not in the same way English does.

Turkish has no direct equivalent of English articles the and a/an in most sentences. So eğlence can mean:

• the fun
• the entertainment
• sometimes just fun or entertainment

The exact meaning depends on context.

Başladı comes from the verb başlamak, meaning to start / to begin.

It breaks down like this:

• başla- = verb stem
• -dı = past tense suffix

Because of vowel harmony, the past tense appears here as -dı, giving başladı = started / began.

It is also third person singular, so it matches eğlence.

Because in Turkish, third person singular often has no extra personal ending in this tense.

For example:

• başladım = I started
• başladın = you started
• başladı = he/she/it started

So başladı already means started with a third-person subject.

Eğlence can mean things like:

• fun
• entertainment
• amusement
• sometimes the party or the festivities, depending on context

So in this sentence, the most natural English meaning depends on the situation. It could refer to the fun itself, an entertainment event, or a party-like activity.

Yes, Turkish word order is flexible.

For example, you could also see:

• Gece eğlence başladı.

That would put more focus on gece.

But the verb usually still stays at the end, and the original sentence is perfectly normal.

A rough guide:

• Eğlence ≈ ey-len-je
• gece ≈ geh-je
• başladı ≈ bash-luh-duh

A few useful points:

• ğ is usually not a hard g sound; it often lengthens the previous vowel or creates a slight glide
• c in Turkish sounds like English j
• ş sounds like English sh

So eğlence does not have a hard g sound.