Kijk omhoog naar de vogels in de lucht.

Kijk is the imperative of kijken (to look). In this sentence, it means Look and is used as a command or instruction.

• kijken = to look
• kijk! = look!

So Kijk omhoog naar de vogels in de lucht is an instruction addressed to someone directly.

A more polite version could be:

• Kijkt u omhoog naar de vogels in de lucht. = Look up at the birds in the air/sky.

Because this is an informal singular imperative.

For many Dutch verbs, the basic imperative is just the stem:

• kijken → kijk
• lopen → loop
• komen → kom

So:

• Kijk! = Look!

You do not use the normal present-tense jij kijkt form here, because this is not a regular statement like you look. It is a command.

Omhoog means up, upward, or upwards.

It tells you the direction of the looking:

• kijk omhoog = look up
• kijk naar de vogels = look at the birds

Together:

• Kijk omhoog naar de vogels = Look up at the birds

Dutch often uses omhoog when talking about upward movement or direction:

• Hij kijkt omhoog. = He looks up.
• De ballon gaat omhoog. = The balloon goes up.

Because kijken usually takes naar when you say what someone is looking at.

• kijken naar iets/iemand = to look at something/someone

So:

• Ik kijk naar de vogels. = I am looking at the birds.

In this sentence:

• omhoog tells the direction: up
• naar de vogels tells the target: at the birds

That is very similar to English look up at the birds.

Usually, this sentence is better as Kijk omhoog naar de vogels.

That is because opkijken naar is also a common Dutch expression meaning to look up to in the figurative sense of to admire or respect someone.

For example:

• Ik kijk op naar mijn leraar. = I look up to my teacher.

So if you say Kijk op naar de vogels, it may sound odd or ambiguous. Omhoog clearly gives the literal physical meaning: look upward.

De vogels means the birds, not just birds.

Here, the article de makes the noun definite. It suggests that the speaker means specific birds, probably the ones visible in the sky.

Also, in Dutch, plural nouns normally take de as their definite article:

• de vogel = the bird
• de vogels = the birds

Without the article:

• vogels = birds in a more general or indefinite sense

Because lucht is a de-word:

• de lucht = the air / the sky

So:

• in de lucht = in the air / in the sky

You simply have to learn the gender/article of each noun. In this case, it is de lucht, not het lucht.

Here, in de lucht means in the air or in the sky.

With birds, Dutch very naturally says:

• vogels in de lucht = birds in the air / birds in the sky

Even though lucht literally means air, it can also be used in contexts where English might prefer sky.

For example:

• Er vliegt een vliegtuig in de lucht. = There is a plane flying in the sky.

So in this sentence, in de lucht describes where the birds are.

It describes de vogels.

The structure is:

• Kijk = command
• omhoog = direction
• naar de vogels = what to look at
• in de lucht = where those birds are

So the sense is:

• Look up at the birds that are in the air/sky.

It is not really saying look in the air by itself; it is specifying which birds.

The order is natural because Dutch often places these elements like this:

1. verb / command → Kijk
2. direction adverb → omhoog
3. prepositional phrase with the object of looking → naar de vogels
4. extra information about that object → in de lucht

So the sentence builds up step by step:

• Look
• up
• at the birds
• in the air

That makes it sound very natural in Dutch.

Yes. That would also be correct.

• Kijk naar de vogels in de lucht. = Look at the birds in the sky.

Adding omhoog makes the upward direction more explicit:

• Kijk omhoog naar de vogels in de lucht. = Look up at the birds in the sky.

So omhoog adds emphasis to the fact that you should raise your gaze.

This is a very common question.

• kijken = to look → active, intentional
• zien = to see → passive, the result of perception

So:

• Kijk naar de vogels. = Look at the birds.
• Ik zie de vogels. = I see the birds.

In this sentence, the speaker is telling someone to direct their eyes somewhere, so kijken is the correct verb.

Yes, it is natural and understandable.

A Dutch speaker might also say:

• Kijk eens omhoog naar de vogels in de lucht.
• Kijk naar de vogels daar in de lucht.
• Kijk omhoog, naar de vogels in de lucht.

But the original sentence is perfectly fine. It sounds like a clear instruction, especially in teaching materials or simple descriptive language.