Momentul este important.

Because Romanian usually puts the definite article at the end of the noun.

• moment = moment / a moment
• momentul = the moment

So -ul here means the.

This is very different from English, where the is a separate word. In Romanian, it is often attached to the noun itself.

Este is the 3rd person singular of the verb a fi = to be.

So here:

• momentul = the moment
• este = is
• important = important

Together: Momentul este important. = The moment is important.

Yes. That is very common.

• este = full form
• e = shorter everyday form

So both are correct:

• Momentul este important.
• Momentul e important.

The full form may sound a little more careful or formal, while e is very natural in speech.

Because the adjective has to agree with the noun.

Moment is a neuter noun in Romanian, but in the singular neuter nouns behave like masculine nouns. So the adjective takes the masculine/neuter singular form:

• important = masculine/neuter singular
• importantă = feminine singular
• importante = feminine/neuter plural

That is why you get:

• Momentul este important.

But in the plural:

• Momentele sunt importante. = The moments are important.

It is neuter.

This is important because Romanian neuter nouns behave:

• like masculine in the singular
• like feminine in the plural

So:

• singular: momentul este important
• plural: momentele sunt importante

That pattern is very common in Romanian neuter nouns.

No.

• Momentul este important. = The moment is important.
• Momentul important = the important moment

The first is a full sentence with the verb este. The second is just a noun phrase.

This is a very important distinction for English speakers.

Yes, but the normal, neutral order is:

subject + verb + adjective

• Momentul este important.

You can change the order for emphasis:

• Important este momentul.

That sounds more marked or literary, something like It is the moment that is important or Important is the moment.

For everyday neutral speech, Momentul este important is the best choice.

A simple English-friendly guide is:

• Momentul ≈ mo-MEN-tool
• este ≈ ES-te or sometimes YES-te
• important ≈ im-por-TANT

A few helpful notes:

• The stress in momentul is on men
• The stress in important is on the last syllable: -tant
• Romanian r is usually tapped or lightly rolled
• The final t in important is pronounced clearly

In standard Romanian, you normally keep the verb to be in sentences like this.

So you say:

• Momentul este important.
• or Momentul e important.

You do not normally say just:

• Momentul important if you mean The moment is important

Because without este/e, that usually becomes the important moment, not a complete sentence.

You would say:

• Momentele sunt importante. = The moments are important.

Changes:

• momentul → momentele
• este → sunt
• important → importante

This shows the neuter pattern clearly:

• singular: important
• plural: importante

You would say:

• Un moment este important.

Here:

• un moment = a moment
• momentul = the moment

So the difference is:

• Un moment este important. = A moment is important.
• Momentul este important. = The moment is important.