القمر في الكون.

A natural Egyptian pronunciation is il-'amar fil-kōn or el-'amar fil-kōn.

A few helpful notes:

• القمر is il-'amar / el-'amar
• في is fi
• الكون is il-kōn / el-kōn
• In fast speech, في الكون often sounds like fil-kōn

Also, in Egyptian Arabic, the letter ق is often pronounced as a glottal stop, so قمر sounds like 'amar rather than qamar.

Because Arabic normally leaves out the verb to be in the present tense.

So a sentence like:

• القمر في الكون

literally looks like:

• the moon in the universe

but it means:

• the moon is in the universe

This is completely normal in both Standard Arabic and Egyptian Arabic.

If you wanted a past meaning, then Arabic would use a verb, for example كان.

في means in, inside, or sometimes at, depending on context.

In this sentence, it marks location, so it connects the noun القمر with the place الكون.

So the structure is:

• القمر = the subject
• في الكون = the location phrase

In speech, في often joins smoothly to the next word, which is why في الكون may sound like fil-kōn.

Because الـ is the Arabic definite article, equivalent to the in English.

So:

• القمر = the moon
• الكون = the universe

Arabic uses الـ very regularly with definite nouns. Since both nouns here are specific and definite, both take الـ.

It is understandable in Egyptian Arabic, but it feels a bit more formal or neutral than strongly colloquial.

Why?

• في is completely normal in Egyptian
• القمر is also normal
• الكون is understood in Egyptian, but it can sound a little more formal or bookish than some everyday expressions

So the sentence is fine, but in casual speech an Egyptian might be more likely to say something more context-specific, depending on what they mean.

Because ق and ك are moon letters.

In Arabic, after الـ, there are two patterns:

• moon letters: the ل in الـ is pronounced
• sun letters: the ل is not pronounced, and the next consonant is doubled

So here:

• القمر → il-qamar / il-'amar in principle, with the l pronounced
• الكون → il-kōn, also with the l pronounced

This is actually a nice coincidence: the word قمر is the word that gives moon letters their name.

Yes. That is also correct.

Adding موجود makes the idea of presence or existence more explicit:

• القمر في الكون = the moon is in the universe
• القمر موجود في الكون = the moon exists / is present in the universe

In everyday Egyptian Arabic, موجود is very common in location sentences, but it is not required.

It is a complete sentence.

In Arabic grammar, this is a nominal sentence:

• القمر = the topic/subject
• في الكون = the predicate, telling us where it is

English usually expects a visible verb like is, but Arabic does not need one in the present tense. So even without a written verb, this is still a full sentence.

Not in Egyptian Arabic.

In normal Egyptian writing and speech, you do not use or pronounce case endings. So the spelling:

• القمر في الكون

is exactly what you would expect.

In fully vocalized Standard Arabic, you might see something like:

• القمرُ في الكونِ

But in Egyptian Arabic, learners usually do not need to produce those endings.

It is grammatically correct, but it is not a very informative sentence, because everything is in the universe.

So it sounds a little unusual unless it appears in a special context, such as:

• a child learning vocabulary
• a science lesson
• a contrast with something impossible or imaginary

In everyday speech, a more natural location sentence might be something like the moon is in the sky or the moon is in space, depending on the context.