Postul este interesant.

Romanian usually puts the definite article at the end of the noun instead of using a separate word like English the.

• post = a post / a job / a position / a fast depending on context
• postul = the post / the job / the position / the fast

Here, -ul is the definite article used with many masculine and neuter singular nouns.

Post is usually a neuter noun in Romanian.

That matters because Romanian neuter nouns behave:

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

So in the singular you get:

• postul
• interesant

But in the plural you would get:

• posturile
• interesante

Este is the 3rd person singular present form of a fi, which means to be.

So:

• eu sunt = I am
• tu ești = you are
• el/ea este = he/she is

In this sentence, este means is.

Normally, no. In a standard sentence like this, Romanian usually keeps the verb a fi.

So the normal forms are:

• Postul este interesant.
• Postul e interesant. — a very common shorter spoken form

Leaving it out completely would usually sound incomplete, except in special styles like headlines or notes.

Because the adjective has to agree with the noun in gender and number.

Since post is neuter, and neuter nouns act like masculine in the singular, the adjective is:

• interesant for masculine/neuter singular

Compare:

• postul este interesant — singular neuter
• cartea este interesantă — singular feminine
• posturile sunt interesante — plural neuter

Yes. It has the neutral, standard Romanian order:

subject + verb + adjective

So:

• Postul = the subject
• este = the verb
• interesant = the adjective

You can change the order for emphasis, for example:

• Interesant este postul.

But that sounds more marked or stylistic. The most natural basic order is Postul este interesant.

Yes. Post can mean different things depending on context, for example:

• job / position
• post / station
• religious fast
• sometimes other related senses such as duty post

So the grammar of the sentence stays the same, but the exact meaning depends on context.

Here, postul is in the nominative singular, because it is the subject of the sentence.

In many situations, Romanian nominative and accusative forms look the same. A useful comparison is:

• postul — nominative/accusative with the definite article
• postului — genitive/dative singular

So in this sentence, postul is simply the subject: the post / the job / the position.

The plural would be:

Posturile sunt interesante.

Changes:

• postul → posturile = the posts / the jobs / the positions
• este → sunt = are
• interesant → interesante

This is a good example of how neuter nouns become feminine-looking in the plural.