Dej kolo sem.

Dej is the singular informal imperative of the verb dát, meaning to give / to put / to place, depending on context.

In Dej kolo sem, it means something like put or bring.

So dej is a command to one person:

• dej = give/put! addressed to you (singular, informal)

Because this sentence is a command.

• dát = infinitive, to give / to put
• dáš = you will give / you give
• dej = give! / put!

So if you want to tell someone to do something, Czech uses the imperative:

• Dej kolo sem. = Put the bike here.

In Czech, the subject is often omitted when it is clear from the verb form.

The form dej already tells you that the speaker is talking to one person informally, so adding ty is usually unnecessary.

• Dej kolo sem. = Put the bike here.
• Ty dej kolo sem. = more emphatic, like You put the bike here.

Kolo most commonly means bicycle or wheel, and in some contexts it can also mean round / round of a competition.

In this sentence, the intended meaning depends on context, but learners will often see it translated as bike or bicycle.

So:

• Dej kolo sem. = Put the bike here.

If the situation were different, it could also theoretically mean:

• Put the wheel here.

Because kolo is the direct object here, and for this noun the nominative and accusative singular are the same.

Kolo is a neuter noun, and many neuter nouns have the same form in both cases:

• nominative: kolo
• accusative: kolo

So although it is the object of the verb, its form does not change.

Here, sem means here, to here, over here with a sense of movement toward the speaker.

That is an important detail. Czech often distinguishes:

• tady / zde = here as a location
• sem = to here, direction toward here
• tam = there
• tamhle / tamhleto etc. = over there

So in Dej kolo sem, sem fits well because something is being moved:

• Put the bike here
• literally: Put the bike to here

Not in this sentence.

Czech learners often notice that sem can also appear as a colloquial spoken form of jsem (I am), but that is a completely different word function.

Here, sem is an adverb of direction, meaning to here.

So in:

• Dej kolo sem.

it definitely means here, not I am.

Yes, Czech word order is flexible, and different orders can sound more natural depending on emphasis.

The basic sentence:

• Dej kolo sem.

Other possible orders:

• Dej sem kolo.
• Kolo dej sem.

These all can be understood, but the emphasis changes:

• Dej kolo sem. = neutral
• Dej sem kolo. = often also very natural, with focus on sem
• Kolo dej sem. = emphasizes the bike

So the original sentence is correct and natural, but not the only possible order.

It is informal singular.

Dej is used when speaking to:

• one person
• someone you address with ty

If you want to be formal or speak to more than one person, use:

• Dejte kolo sem.

So:

• Dej kolo sem. = informal singular
• Dejte kolo sem. = formal singular or plural

By itself, it is a direct command, so it can sound neutral, firm, or rude depending on tone and situation.

Czech imperatives are often more direct than English ones. If you want to soften it, you can add prosím:

• Dej kolo sem, prosím.
• Prosím, dej kolo sem.

That makes it more like:

• Please put the bike here.

So the sentence itself is not automatically rude, but tone matters.

This is about aspect, which is very important in Czech.

• dát is perfective
• dávat is imperfective

The imperative dej usually suggests a single completed action:

• Dej kolo sem. = Put the bike here.

The imperative dávej can suggest a more ongoing, repeated, or process-like action, and in many situations it would sound less natural here.

So for a simple one-time command, dej is the normal choice.

A simple approximation is:

• Dej ≈ day
• kolo ≈ KO-lo
• sem ≈ sem with a short e, not like English same

Rough stress:

• DEJ KO-lo sem

A more careful pronunciation is approximately:

• [dɛj kolo sɛm]

Czech stress is usually on the first syllable of each word.

Yes. Depending on the situation, English may translate it as:

• Put the bike here
• Bring the bike here
• Give me the bike here in a less common context

That is because dát has a broad range of meanings involving giving, placing, or putting. The exact English translation depends on what is happening in the scene.

So the Czech sentence is simple, but English may choose different verbs depending on context.