Elrejtjük a kulcsot.

It can be broken down like this:

• el- = a verbal prefix
• rejt = the verb stem hide
• -jük = we
  • present tense + definite verb ending
• a = the
• kulcsot = key in the accusative case, meaning it is the direct object

So the sentence literally has the structure hide-away-we the key-ACC.

Hungarian usually does not need a separate subject pronoun if the verb ending already shows the subject.

Here, -jük tells you the subject is we.

So:

• elrejtjük = we hide it / we hide the ...
• mi elrejtjük = we hide... with extra emphasis on we

The pronoun mi is normally left out unless you want contrast or emphasis.

Because Hungarian has two kinds of verb conjugation:

• indefinite conjugation
• definite conjugation

You use the definite conjugation when the verb has a definite object, such as:

• a kulcsot = the key
• a specific, known key

That is why the verb is elrejtjük.

Compare:

• Elrejtünk egy kulcsot. = We hide a key.
• Elrejtjük a kulcsot. = We hide the key.

So the form -jük matches the fact that the object is definite.

Because kulcs is the direct object of the sentence, and Hungarian marks direct objects with the accusative ending, usually -t.

So:

• kulcs = key
• kulcsot = key + accusative = the key as the thing being hidden

The extra -o- appears as a linking vowel, which makes the word easier to pronounce.

Hungarian often inserts a vowel before certain endings when needed for pronunciation.

So instead of an awkward form like kulcst, Hungarian uses:

• kulcs + -ot = kulcsot

The vowel also follows vowel harmony patterns. Since kulcs contains the back vowel u, the linking vowel here is o.

The prefix el- often gives a sense of:

• moving something away
• bringing an action to completion
• making the result more definite

So rejt is related to hide, while elrejt is more like:

• hide away
• conceal completely

In this sentence, elrejtjük sounds more natural than a bare rejtjük if you mean actually putting the key out of sight.

Grammatically, it is present tense.

However, in Hungarian, present tense can often be used for the future if the context makes that clear.

So Elrejtjük a kulcsot can mean either:

• We hide the key
• We are hiding the key
• We will hide the key

The exact meaning depends on context.

A means the, so a kulcsot means the key.

This shows that the speaker means a specific key, not just any key.

That matters in Hungarian, because a definite object also affects the verb form:

• a kulcsot → definite object
• therefore elrejtjük → definite conjugation

If you said egy kulcsot (a key), the verb would normally change:

• Elrejtünk egy kulcsot.

No. Hungarian word order is quite flexible, and it often changes to show focus or emphasis.

Elrejtjük a kulcsot is a natural neutral sentence.

But other orders are possible, depending on what you want to stress. For example:

• A kulcsot rejtjük el. = It is the key that we are hiding.
• Mi rejtjük el a kulcsot. = We are the ones hiding the key.

So the basic meaning stays similar, but the emphasis changes.

Yes. Hungarian verbal prefixes often separate from the verb in certain sentence types, especially with:

• negation
• focus
• some question patterns

For example:

• Elrejtjük a kulcsot. = We hide the key.
• Nem rejtjük el a kulcsot. = We do not hide the key.

So in the sentence you were given, the prefix stays attached because the sentence is neutral and affirmative.

No. In fact, leaving out mi is more normal.

Hungarian usually drops subject pronouns when the verb ending already makes the subject clear.

So:

• Elrejtjük a kulcsot. = normal
• Mi elrejtjük a kulcsot. = more emphatic, like we hide the key

That is one of the big differences from English.