Hiába próbáljuk ki a számkódot, nem tudjuk kinyitni a lakatot.

Hiába means something like in vain, it’s no use, or however much.

In this sentence, it gives the idea:

• Even if we try the number code
• No matter how much we try the number code
• Trying the number code is useless

So Hiába próbáljuk ki a számkódot... means that the action is being done, but it still does not lead to success.

Because Hungarian is using the definite conjugation here.

Both parts of the sentence involve a definite object:

• a számkódot = the number code
• a lakatot = the padlock

When the verb has a definite direct object, Hungarian often uses the definite verb ending.

So:

• próbálunk = we try (indefinite / no specific object)
• próbáljuk = we try it / we try the specific thing

And similarly:

• tudunk kinyitni valamit = we can open something
• tudjuk kinyitni a lakatot = we can open the padlock

The second one is especially important: with tud + infinitive, the definite object of the infinitive can determine the definite conjugation of the finite verb.

Próbáljuk ki comes from kipróbál, which means to try out, to test, or to give something a try.

So here:

• próbáljuk ki a számkódot = we try out the number code

This is a little different from simply próbálni in the sense of attempting to do something.

Compare:

• megpróbáljuk kinyitni a lakatot = we try to open the padlock
• kipróbáljuk a számkódot = we try out the code

So kipróbálni focuses on testing the code itself, not directly on the act of opening.

This is about verbal prefixes.

Hungarian often has verbs with prefixes like:

• kipróbál = try out
• kinyit = open
• bemegy = go in
• leír = write down

These prefixes are sometimes attached to the verb, and sometimes separated.

In a neutral statement

The prefix usually stays attached:

• Kipróbáljuk a számkódot.

But if something else is in focus, or with certain structures

the prefix often moves after the finite verb:

• Hiába próbáljuk ki a számkódot...

Here hiába comes before the verb and breaks up the prefix-verb unit.

Why is kinyitni still one word?

Because it is an infinitive, not the main finite verb of the clause. In this structure, the prefix usually stays attached:

• nem tudjuk kinyitni a lakatot

So this contrast is very normal:

• próbáljuk ki
• kinyitni

Because they are in the accusative case, which marks the direct object.

Hungarian direct objects usually get -t, but sometimes an extra vowel appears before it.

So:

• számkód → számkódot
• lakat → lakatot

This -ot is basically the accusative ending here.

English shows the direct object mostly by word order:

• We try the code
• We open the padlock

Hungarian can show it morphologically with the accusative ending.

It can potentially suggest either, because tud with an infinitive can express both:

• ability = can
• know-how = know how to

But in this sentence, the most natural meaning is:

• we can’t open the padlock

The context is practical failure, not lack of knowledge in an abstract sense.

So nem tudjuk kinyitni a lakatot is best understood as:

• we can’t open the padlock
• or we are unable to open the padlock

It is not written separately, because Hungarian usually does not need subject pronouns when the verb ending already shows the subject.

Here the ending -juk tells you that the subject is we and that the verb is in the definite conjugation.

So:

• próbáljuk = we try it / we try the specific thing
• tudjuk = we can it / we can do it in this grammatical sense

If you added mi = we, it would sound more emphatic:

• Hiába próbáljuk ki a számkódot... = neutral
• Hiába mi próbáljuk ki... = not natural here
• Mi hiába próbáljuk ki a számkódot... = emphasizes we

Usually, Hungarian leaves mi out unless it is needed for contrast or emphasis.

Because both nouns are definite:

• a számkódot = the number code
• a lakatot = the padlock

Hungarian uses a / az as the definite article, like English the.

This suggests that the speaker has specific things in mind:

• a particular code
• a particular padlock

That also connects to the definite conjugation on the verbs.

Yes, but changing the word order in Hungarian often changes the focus or the emphasis, not just the style.

The given sentence is natural:

• Hiába próbáljuk ki a számkódot, nem tudjuk kinyitni a lakatot.

This presents hiába as the important frame: it’s no use.

A more neutral sentence without hiába might look like:

• Kipróbáljuk a számkódot, de nem tudjuk kinyitni a lakatot.

But with hiába, the order hiába + verb + prefix is very typical.

So yes, Hungarian word order is flexible, but the version you have is the normal, idiomatic way to express this meaning.

They are the same prefix ki-, but they contribute slightly different meanings depending on the verb.

In general, ki- often suggests out, fully, or to completion.

Examples:

• kipróbál = try out
• kinyit = open
• kivesz = take out

In kipróbál, the idea is test something out.

In kinyit, the idea is open something up.

So it is the same prefix, but its exact effect depends on the verb it combines with. This is very common in Hungarian: prefixes are productive, but their meanings are not always perfectly predictable word-for-word.