Jeg hilser på min nabo om morgenen.

In Danish, at hilse på nogen means to greet someone or to say hello to someone.

So in this sentence:

• Jeg hilser på min nabo = I greet my neighbor

The preposition på is part of the expression here.
Without på, hilse can be used differently, for example in meanings like send regards:

• Hils din mor = Say hello to your mother from me

So for directly greeting a person you meet, hilse på is very common.

Not really. Although på often means on, in hilse på it is just part of the fixed verb expression.

So you should learn:

• at hilse på nogen = to greet someone

It is better not to translate på word-for-word in this sentence.

In Danish, when you use a possessive like min, din, hans, vores, etc., the noun usually does not take the definite ending.

So:

• min nabo = my neighbor
• not min naboen

Compare:

• en nabo = a neighbor
• naboen = the neighbor
• min nabo = my neighbor

This is different from English, where the and possessives are separate words. In Danish, the definite meaning is already covered by min.

Because om morgenen is a common expression meaning in the morning / in the mornings.

Here:

• morgen = morning
• morgenen = the morning

After om, Danish often uses the definite form in general time expressions:

• om morgenen = in the morning
• om aftenen = in the evening
• om natten = at night

This does not necessarily mean one specific morning. It is just the normal idiomatic way to say it.

No. Om morgenen usually means in the morning or in the mornings, as a general time expression.

If you want to say this morning, Danish would usually use:

• i morges = this morning

So:

• Jeg hilser på min nabo om morgenen = I greet my neighbor in the morning / in the mornings
• Jeg hilste på min nabo i morges = I greeted my neighbor this morning

Usually, yes. Because it is in the present tense and uses a general time phrase, it often suggests a repeated action or habit.

So Jeg hilser på min nabo om morgenen is often understood as:

• I greet my neighbor in the morning
• or more naturally in English, I greet my neighbor every morning

Danish present tense can often express habits without needing a special form.

Hilser is the present tense of at hilse.

The verb forms are:

• at hilse = to greet
• hilser = greet / greets
• hilste = greeted
• har hilst = have/has greeted

With jeg, Danish still uses the same present-tense form:

• jeg hilser = I greet

Unlike English, Danish verbs do not change much depending on the subject.

This is the normal Danish word order for a main clause:

• Subject + verb + other elements

So:

• Jeg = subject
• hilser = verb
• på min nabo = object/prepositional phrase
• om morgenen = time expression

Danish often places time expressions later in the sentence, though they can also come first for emphasis.

Yes, absolutely.

If you move Om morgenen to the front, Danish uses normal V2 word order, which means the verb comes second:

• Om morgenen hilser jeg på min nabo

Notice that it is:

• Om morgenen hilser jeg...
• not Om morgenen jeg hilser...

This version emphasizes the time: In the morning, I greet my neighbor.

In modern Danish, nouns are usually grouped as common gender or neuter, not masculine/feminine in the same way English learners may expect from other European languages.

Nabo is a common gender noun, so it takes:

• en nabo = a neighbor
• naboen = the neighbor

That is why you would not use et nabo.

Because nabo here is singular.

You can see that from:

• min nabo = my neighbor (singular)

The plural would be:

• naboer = neighbors
• mine naboer = my neighbors

So:

• Jeg hilser på min nabo = I greet my neighbor
• Jeg hilser på mine naboer = I greet my neighbors

A rough guide is:

• Jeg sounds a bit like yai
• hilser sounds roughly like HIL-ser
• på sounds roughly like paw with a rounded vowel

So the middle part is approximately:

• hilser på ≈ HIL-ser paw

But natural Danish pronunciation is softer and more blended than English spelling suggests. In connected speech, the sounds may run together quite a bit.

Not if you want the same meaning.

• om morgenen = in the morning / in the mornings as a general time expression
• om en morgen would mean something more like one morning, which is a different idea and sounds unusual in many contexts

For a single unspecified occasion, Danish would more naturally say something like:

• en morgen = one morning
• en morgen hilste jeg på min nabo = one morning I greeted my neighbor

So in your sentence, om morgenen is the correct idiomatic choice.

Danish present tense is not divided the same way as English simple present and present continuous.

So jeg hilser can sometimes correspond to:

• I greet
• I am greeting

But in this sentence, with om morgenen, the most natural interpretation is habitual:

• I greet my neighbor in the morning
• I greet my neighbor every morning

If you wanted to strongly emphasize an action happening right now, Danish would usually rely on context or use another construction.