Το καβούρι κρύβεται κάτω από την άμμο, αλλά το παιδί το βλέπει και γελάει.

Because το can have different grammatical jobs in Greek.

In this sentence:

• Το καβούρι = the crab
  Here το is the neuter singular definite article.

• το παιδί = the child
  Again, το is the neuter singular definite article.

• το βλέπει = sees it
  Here το is not an article. It is the weak object pronoun meaning it.

So Greek uses the same form το for:

• the with a neuter singular noun
• it as a neuter singular direct object pronoun

You tell the difference from the word’s position and function in the sentence.

Because both nouns are neuter singular.

Greek nouns have gender, and the definite article changes depending on:

• gender
• number
• case

Here:

• το καβούρι = neuter singular
• το παιδί = neuter singular

So both take το in the nominative/accusative singular.

A learner should remember that Greek grammatical gender is not always about biological sex. For example:

• το παιδί means the child, and grammatically it is neuter.

Because άμμο is the object of the preposition από.

The phrase is:

• κάτω από την άμμο = under the sand

After από, Greek uses the accusative case, so:

• nominative: η άμμος = the sand
• accusative: την άμμο = the sand

So the article and noun change form because of case:

• η άμμος
• την άμμο

κάτω από is a very common expression meaning under / beneath.

It is made of:

• κάτω = down / below
• από = from, but in this expression it helps form under

So:

• κάτω από την άμμο = under the sand

You can think of κάτω από as a fixed phrase meaning under.

More examples:

• κάτω από το τραπέζι = under the table
• κάτω από το νερό = under the water

Here κρύβεται means hides or is hiding.

This verb comes from κρύβομαι, which is a middle/passive-form verb in Modern Greek. In many cases, verbs with passive endings do not have a passive meaning in English.

So:

• κρύβει = hides something
• κρύβεται = hides / hides itself / is hiding

In this sentence:

• Το καβούρι κρύβεται = The crab hides / is hiding

A very natural English translation is simply The crab is hiding.

Because Greek often expresses that idea through the verb form itself.

With κρύβομαι / κρύβεται, the meaning already includes the idea of hiding oneself or simply being hidden / hiding.

So Greek does not need a separate reflexive word here.

English often says:

• The crab hides
• The crab is hiding

Greek says:

• Το καβούρι κρύβεται

Because weak object pronouns in Modern Greek normally come before the conjugated verb.

So:

• το βλέπει = sees it

This is very normal Greek word order.

Compare:

• Βλέπει το καβούρι = He/She sees the crab
• Το βλέπει = He/She sees it

The pronoun usually comes before the finite verb:

• με βλέπει = sees me
• σε ξέρει = knows you
• το θέλω = I want it

It refers to το καβούρι.

Even though there is another neuter noun in the sentence, το παιδί, the meaning and structure make it clear:

• το παιδί is the subject of βλέπει
• το is the direct object
• so the child sees it, meaning the crab

Greek often uses these short object pronouns instead of repeating the noun.

Greek often drops subjects because the verb ending already gives information, but it does not have to.

Here το παιδί is included because it introduces or emphasizes the subject clearly:

• ... αλλά το παιδί το βλέπει ... = ... but the child sees it ...

Without το παιδί, you would have:

• ... αλλά το βλέπει και γελάει which would mean something like ... but he/she sees it and laughs

So keeping το παιδί makes the sentence clearer and more natural in context.

Because they both agree with the same subject: το παιδί.

Both are third person singular present tense:

• βλέπει = he/she/it sees
• γελάει = he/she/it laughs

Since το παιδί is singular, the verbs are singular too.

In Greek, παιδί is grammatically neuter, but for a child in general English usually says the child sees it and laughs, not it sees it and laughs.

Yes, both γελάει and γελά are used in Modern Greek.

They are two common present-tense forms of the same verb:

• γελάει
• γελά

Both mean:

• he/she laughs
• he/she is laughing

In everyday Greek, both are natural.
γελάει may sound a bit fuller or slightly more conversational in some contexts, but both are standard.

It can express either, depending on context.

Greek present tense often covers both:

• simple present: hides, sees, laughs
• present continuous: is hiding, is seeing, is laughing

So this sentence could be understood as:

• The crab hides under the sand, but the child sees it and laughs or
• The crab is hiding under the sand, but the child sees it and laughs

In natural English, the second version often sounds better for this kind of scene.

Because αλλά means but, and it connects two clauses.

The sentence has two main parts:

• Το καβούρι κρύβεται κάτω από την άμμο
• αλλά το παιδί το βλέπει και γελάει

Greek punctuation here works much like English:

• comma before but when joining clauses is very common

So the comma helps separate the contrast:

• The crab is hiding..., but the child sees it...

It can mean either one.

• και = and
• γελάει = laughs / is laughing

So:

• το βλέπει και γελάει = sees it and laughs or more naturally in context:
• sees it and starts laughing / sees it and is laughing

Greek present tense is flexible here, and English chooses the version that sounds most natural in context.

Greek word order is more flexible than English, though not completely free.

This sentence is very natural:

• Το καβούρι κρύβεται κάτω από την άμμο, αλλά το παιδί το βλέπει και γελάει.

But Greek could rearrange parts for emphasis, for example:

• Κάτω από την άμμο κρύβεται το καβούρι...
• ...αλλά το βλέπει το παιδί και γελάει.

However, not every rearrangement sounds equally neutral. The original version is a straightforward, standard sentence for learners.

Here are the main noun phrases:

• Το καβούρι: nominative
  It is the subject of κρύβεται.

• την άμμο: accusative
  It follows the preposition από in κάτω από την άμμο.

• το παιδί: nominative
  It is the subject of βλέπει and γελάει.

• το in το βλέπει is not a noun phrase; it is an accusative object pronoun.

So a learner can see both nominative and accusative in this one sentence.