Η κοπέλα και το κορίτσι γελάνε όταν πέφτει το παγάκι στο ποτήρι.

Greek definite articles change for gender, number, and case.

In this sentence:

• η κοπέλα = feminine singular
• το κορίτσι = neuter singular
• το παγάκι = neuter singular
• στο ποτήρι = σε + το, meaning in/into the glass

So Greek does not use one single word like English the. The article has to match the noun.

They are similar, but not identical.

• κορίτσι usually means girl, often a child or younger female
• κοπέλα usually means girl/young woman

So the sentence mentions two different female people, and the choice of word suggests they may be of different ages or simply viewed differently.

Because these are two separate nouns, each with its own gender and article:

• η κοπέλα
• το κορίτσι

In Greek, when two nouns are joined by και (and), each noun normally keeps its own article if both are definite.

This is especially necessary here because the nouns have different genders.

Because the subject is plural in meaning:

• η κοπέλα και το κορίτσι = the girl/young woman and the girl = two people

So the verb must be 3rd person plural.

γελάνε means they laugh / are laughing.

No. Greek has more than one common 3rd person plural form for some verbs.

For γελάω / γελώ (to laugh), you may hear:

• γελάνε
• γελάν
• γελούν

In everyday spoken Greek, γελάνε is very common and natural.

So this sentence sounds normal and conversational.

Because πέφτει belongs to the όταν clause, and its subject is only το παγάκι:

• όταν πέφτει το παγάκι στο ποτήρι

So the verb is singular because the ice cube is singular.

The two people are the subject of γελάνε, not of πέφτει.

όταν means when.

It introduces a time clause:

• γελάνε όταν πέφτει το παγάκι στο ποτήρι
• they laugh when the ice cube falls into the glass

A common pattern in Greek is:

• main clause + όταν
  • verb

Here it connects the laughing with the moment when the ice cube falls.

Greek often uses the present tense after όταν for events that are:

• habitual
• repeated
• general
• described as they happen

So όταν πέφτει το παγάκι στο ποτήρι can sound like:

• when the ice cube falls into the glass
• whenever the ice cube falls into the glass

It does not have to mean present time only. Greek present tense is often broader than English learners first expect.

παγάκι is the normal word for ice cube.

It comes from πάγος (ice) with the diminutive ending -άκι, which often gives the sense of small.

So:

• πάγος = ice
• παγάκι = little piece of ice, usually ice cube

This is the most natural word in everyday Greek for an ice cube.

In this sentence, it most naturally means into the glass, because the verb πέφτει describes movement.

• στο = σε + το
• σε can mean in, on, to, or into, depending on context

So although Greek uses σε, English may translate it differently depending on the verb.

With πέφτει (falls), into the glass is usually the best interpretation.

The subject nouns are in the nominative:

• η κοπέλα
• το κορίτσι
• το παγάκι

After σε, Greek normally uses the accusative:

• στο ποτήρι = σε + το ποτήρι

In this particular noun, ποτήρι, the nominative and accusative forms look the same, which is very common with neuter nouns.

Yes. Greek word order is more flexible than English.

The neutral order here is:

• Η κοπέλα και το κορίτσι γελάνε όταν πέφτει το παγάκι στο ποτήρι.

But Greek could move things around for emphasis, for example:

• Όταν πέφτει το παγάκι στο ποτήρι, η κοπέλα και το κορίτσι γελάνε.

That still means basically the same thing, but the focus shifts slightly to the when part.

Yes, in normal reading it means two different people:

• one is referred to as κοπέλα
• the other as κορίτσι

If Greek wanted to describe one person in two ways, it would usually be written differently and the context would make that clear.

So here you should understand it as a compound subject: person A and person B.

It can be either, depending on context.

Greek present tense often covers both:

• they laugh
• they are laughing

So γελάνε does not force a strict distinction the way English sometimes does.

Context decides whether it is:

• a general/habitual event
• or something happening right now in a scene

Greek uses the definite article more broadly and more regularly than English.

Here we get:

• η κοπέλα
• το κορίτσι
• το παγάκι
• το ποτήρι inside στο ποτήρι

This often sounds perfectly natural in Greek even where English might prefer a or sometimes no article at all. So learners should get used to Greek being more article-friendly than English.