Puer pomum e mensa tollit et sorori ostendit.

Puer is in the nominative singular, which is the case normally used for the subject of a finite verb. So puer is the boy who is doing the actions.

It is also worth noticing that puer is a second-declension masculine noun, even though it does not end in -us. Its dictionary form is puer, pueri.

Here pomum is the direct object of tollit, so it is in the accusative singular: the boy takes an apple.

Because pomum is a neuter noun of the second declension, its nominative and accusative singular look the same. So the form pomum could be nominative or accusative in isolation, but in this sentence its role is clear from the syntax: puer is the subject, so pomum is the object.

The preposition e/ex means out of or from, and it takes the ablative case. That is why the noun appears as mensa, the ablative singular of mensa.

Both e and ex are forms of the same preposition. Very roughly, e is common before consonants and ex before vowels, but Latin authors use both, and the choice is not always rigid. So e mensa is perfectly normal.

Without the preposition, mensa by itself would not clearly express from the table.

It is ablative singular. The reason is simple: e/ex always governs the ablative. So:

• mensa = table
• e mensa = from the table

This is a very common Latin pattern: a preposition plus a noun in the case that the preposition requires.

Tollit is third-person singular present active indicative of tollo, tollere. It means he/she takes, lifts, picks up, or removes, depending on context.

Here, with e mensa, the sense is something like takes up from the table or picks up from the table.

Latin verbs usually already show the person and number of the subject. The ending of tollit tells you the subject is third-person singular: he, she, or it.

Because of that, Latin often leaves subject pronouns unstated unless they are needed for emphasis or contrast. So instead of saying he takes, Latin can simply say tollit.

The direct object is understood from the previous clause. Latin often leaves out words that are obvious from context.

So:

• Puer pomum e mensa tollit = The boy takes an apple from the table
• et sorori ostendit = and shows it to his sister

English often uses it here, but Latin does not have to.

Because sorori is dative singular, and the dative is commonly used for the indirect object: the person to whom something is given, said, shown, and so on.

With ostendit:

• the thing shown is the direct object: pomum
• the person it is shown to is the indirect object: sorori

So sorori ostendit means he shows it to his sister.

Latin often leaves possession unexpressed when it is obvious from context, especially with family relationships. So sorori can naturally be understood as to his sister here.

If Latin wanted to make the possession explicit, it could add a possessive such as suae, but it does not have to.

In this sentence, ostendit is understood as third-person singular present active indicative of ostendo, ostendere: he shows.

A useful extra point: the spelling ostendit can also be a perfect form, meaning he showed or has shown. So by itself it is ambiguous. In a sentence like this, the context and the given meaning tell you that the present tense is intended.

No. Latin word order is much freer than English word order because the case endings show how the words function.

This sentence is perfectly natural, but Latin could rearrange the words and still keep the same basic meaning, for example by moving pomum or e mensa for emphasis. What matters most is not position alone, but the forms of the words:

• puer = nominative subject
• pomum = accusative direct object
• mensa after e = ablative
• sorori = dative indirect object

So word order in Latin often reflects emphasis or style, not just grammar.