Na stole už leží sešit, pravítko a dvě pastelky, protože můj syn chce kreslit ještě před večeří.

Because na can take different cases depending on meaning:

• na stůl = onto the table → motion toward a destination, so it uses the accusative
• na stole = on the table → location, so it uses the locative

Here the things are already there, so Czech uses the locative: na stole.

Also note the noun changes form:

• dictionary form: stůl
• locative singular: stole

This stem change is normal for this noun.

Už means already.

So Na stole už leží... gives the idea that the notebook, ruler, and crayons are already lying on the table now.

It often signals that something has happened earlier than expected or is true at this point already.

Czech often prefers a more specific verb of position where English might simply use is/are.

• leží = lies / is lying
• je / jsou = is / are

So:

• Na stole už leží sešit... sounds natural and vivid: the items are lying on the table
• Na stole už je sešit... is possible in some contexts, but it is less specific

With flat objects like a notebook, ruler, or crayons on a table, ležet is very natural.

In this form, it can be both 3rd person singular and 3rd person plural.

For ležet in the present tense:

• on leží = he/it lies
• oni leží = they lie

So even though the subject is a list of several things (sešit, pravítko a dvě pastelky), the form leží still works perfectly.

They are the things doing the action of lying on the table, so they are in the nominative case.

Breakdown:

• sešit = nominative singular
• pravítko = nominative singular
• dvě pastelky = numeral + nominative plural

This whole group is the subject of leží.

Because pastelka is a feminine noun.

With the number 2, Czech uses:

• dva for masculine nouns
• dvě for feminine and neuter nouns

So:

• dva sešity = two notebooks
• dvě pastelky = two crayons
• dvě pravítka = two rulers

Also, after 2, 3, 4, the noun is usually in the nominative plural:

• dvě pastelky
• tři pastelky
• čtyři pastelky

Můj means my, and it has to agree with the noun it describes.

Since syn is:

• masculine
• singular
• nominative

the correct form is můj:

• můj syn = my son

Compare:

• moje dcera = my daughter
• moje dítě = my child
• moji synové = my sons

So the form of my changes depending on the noun.

Because Czech, like English, uses want + infinitive.

• chce = wants
• kreslit = to draw

So:

• můj syn chce kreslit = my son wants to draw

The verb chtít is conjugated, while the second verb stays in the infinitive.

Other similar examples:

• chci jít = I want to go
• chce spát = he/she wants to sleep
• chtějí hrát = they want to play

This is a very common point of confusion.

In this sentence:

• už = already
• ještě = here something like still / even / as early as

So:

• Na stole už leží... = the items are already on the table
• ještě před večeří = before dinner, with a nuance like even before dinner or already before dinner

So the two words are not doing the same job.

A simple way to remember them here:

• už points to something that is true already now
• ještě adds emphasis to the time phrase: even before dinner

Because před takes the instrumental case when it means before or in front of.

So:

• dictionary form: večeře = dinner
• after před: večeří

That gives:

• před večeří = before dinner

This is true both in time expressions and physical location:

• před večeří = before dinner
• před domem = in front of the house

Literally, it is still/even before dinner, but in natural English it usually means:

• before dinner
• even before dinner
• already before dinner

The extra word ještě adds emphasis. It suggests that the son wants to draw as early as before dinner, not later.

So it is a bit stronger than just:

• před večeří = before dinner

Because protože means because and introduces a subordinate clause.

Czech normally puts a comma before subordinate clauses:

• ..., protože můj syn chce kreslit ještě před večeří.

So the sentence has:

• main clause: Na stole už leží sešit, pravítko a dvě pastelky
• subordinate clause: protože můj syn chce kreslit ještě před večeří

This comma is standard Czech punctuation.

Czech word order is fairly flexible, but the version given sounds natural.

Na stole už leží... works well because it starts with the place, then gives the time nuance už, and then the verb and subject.

You could hear other versions depending on emphasis, for example:

• Už na stole leží sešit...
• Sešit, pravítko a dvě pastelky už leží na stole...

But the original sentence is a very normal way to present the scene: first where, then what is there, then why.