Кубик на столі.

In Ukrainian, the verb to be is usually left out in the present tense.

So:

• Кубик на столі. = The cube/block is on the table.

Literally, Ukrainian just says something like Cube on table.

This is completely normal.
If you add є, it can sound more emphatic, more formal, or sometimes stylistically different:

• Кубик є на столі.

But in everyday speech, Кубик на столі is the most natural way to say it.

Кубик comes from куб (cube) and often means small cube because -ик is a very common diminutive-style ending.

Depending on context, кубик can mean:

• a small cube
• a block
• a toy cube
• sometimes a die / dice cube

So the exact English translation depends on the situation. Grammatically, though, it is just the noun being talked about.

Because на can mean different things depending on whether there is location or movement.

Here, the meaning is location: the cube is on the table.
That requires the noun after на to be in the locative case:

• на столі = on the table

If there were movement onto the table, Ukrainian would usually use the accusative:

• на стіл = onto the table

So:

• Кубик на столі. = it is located there
• Поклади кубик на стіл. = put the cube onto the table

Столі is the locative singular form of стіл (table).

The forms are:

• стіл = nominative singular
• столу / стола = genitive singular
• столу / столові = dative singular
• стіл = accusative singular
• столом = instrumental singular
• столі / столу = locative singular

After на when it means on in the sense of location, Ukrainian commonly uses the locative, so стіл becomes столі.

Because кубик is the subject of the sentence, and subjects normally appear in the nominative case.

So:

• кубик = nominative singular

The noun that changes here is стіл, because it comes after the preposition на and needs the locative form:

• стіл → столі

No. Ukrainian does not use articles like English a/an and the.

So Кубик на столі could mean:

• A cube is on the table
• The cube is on the table

Which one sounds best in English depends on context.

Ukrainian usually shows definiteness through:

• context
• word order
• emphasis
• sometimes demonstratives like цей (this) or той (that)

Yes. Ukrainian word order is fairly flexible, although different orders can sound slightly different in emphasis.

For example:

• Кубик на столі. = neutral statement
• На столі кубик. = puts a little more focus on the location or sounds like There is a cube on the table
• Кубик є на столі. = possible, but less neutral in everyday speech

The most basic learner-friendly version here is Кубик на столі.

Here на means on.

It is one of the most common Ukrainian prepositions. Its meaning depends on context:

• на столі = on the table
• на стіл = onto the table

So the preposition itself stays the same, but the case after it changes depending on whether you mean:

• location → locative
• direction/movement → accusative

A simple pronunciation guide is:

KOO-byk na sto-LEE

The stress is:

• ку́бик
• столі́

So the full sentence is:

Ку́бик на столі́.

A few sound notes:

• и in кубик is not exactly the English ee sound
• і in столі is like ee in see
• л in столі is a clear l

It can be both.

Grammatically, it is a complete Ukrainian sentence because Ukrainian often omits is in the present tense.

It can also sound like:

• a very simple description
• a textbook example
• a picture caption
• a basic observation

So even though it is short, it is fully natural Ukrainian.