Στο τέλος του πάρτι έσκασε το μπαλόνι και το μικρό παιδί τρόμαξε, αλλά μετά γέλασε.

Στο is the contraction of σε + το.

• σε = in / at / to
• το = the for a neuter singular noun

So στο τέλος literally means at the end. This contraction is very common in Greek:

• σε + τον = στον
• σε + τη(ν) = στη(ν)
• σε + το = στο

Στο τέλος by itself means at the end, but του πάρτι tells you the end of what. Greek uses the genitive here, just like English uses of:

• το τέλος = the end
• του πάρτι = of the party

So στο τέλος του πάρτι means at the end of the party.

Because it depends on τέλος. In Greek, nouns like τέλος often take a genitive phrase after them to mean of something.

So:

• το τέλος του πάρτι = the end of the party

The genitive is shown mainly by the article του here. The noun πάρτι itself does not change form.

Πάρτι is a loanword, and in Modern Greek it is usually indeclinable, meaning its form stays the same in different cases.

So you get:

• το πάρτι
• του πάρτι
• στο πάρτι

The article changes, but πάρτι stays πάρτι.

In Greek, grammatical gender is not always the same as natural gender. Παιδί is grammatically neuter, even though it refers to a human being.

That is why you get:

• το παιδί
• το μικρό παιδί

This is very normal in Greek. Other words for young beings are often neuter too.

Here μικρό is an adjective meaning small / little, and it agrees with παιδί.

Since παιδί is:

• neuter
• singular
• nominative

the adjective is also:

• neuter
• singular
• nominative

So:

• το = the
• μικρό = little / small
• παιδί = child

Together: the little child.

Έσκασε is the normal verb for something like a balloon, tire, or bubble bursting / popping. The dictionary form is σκάω.

So:

• Το μπαλόνι έσκασε = The balloon popped

This verb can have other meanings in other contexts, but with μπαλόνι it clearly means popped / burst.

Greek word order is more flexible than English word order. The subject does not always have to come first.

Both of these are possible:

• Το μπαλόνι έσκασε
• Έσκασε το μπαλόνι

The version in your sentence sounds very natural in narration, where the event is being presented first: the balloon popped.

They are:

• έσκασε → σκάω = to pop / burst
• τρόμαξε → τρομάζω = to get frightened / to frighten
• γέλασε → γελάω or γελώ = to laugh

A learner often notices that many past tense forms in Greek end in -σε in the third person singular, but the dictionary form is different.

They are all in the aorist, which is the tense/aspect Greek commonly uses for single completed events in a story.

That fits this sentence well:

1. the balloon popped
2. the child got scared
3. then the child laughed

Greek uses the aorist here because these are seen as whole events, not as ongoing actions.

Because Greek often leaves out the subject when it is already understood from the context. This is very common.

So after το μικρό παιδί τρόμαξε, Greek does not need to repeat το μικρό παιδί again. The subject of γέλασε is understood to be the same child.

English usually repeats the subject more often, but Greek often does not.

Here μετά means afterwards / then.

So:

• αλλά μετά γέλασε = but afterwards it laughed / but then the child laughed

In other contexts, μετά can also function like after before a noun, but here it is simply an adverb meaning then / afterwards.

At the beginning of a Greek word, μπ is usually pronounced like b. So μπαλόνι sounds roughly like ba-LO-ni.

A few helpful points:

• μπ at the start = usually b
• the stress is on -λό-
• ι sounds like ee in see

So the word is approximately bah-LOH-nee.