Hidratarea este importantă.

Because Romanian often uses the definite form of an abstract noun when talking about a concept in a general way.

• hidratare = hydration / hydrating
• hidratarea = the hydration, but in natural English this is often just hydration

So Hidratarea este importantă is the normal way to say Hydration is important.

The -a at the end is the definite article, and in Romanian it is attached to the noun instead of being a separate word.

It comes from:

• hidratare = the noun hydration
• -a = the feminine singular definite article

So:

• hidratare → hidratarea

This is very common in Romanian. The article is usually added to the end of the noun:

• carte → cartea = the book
• educație → educația = the education
• hidratare → hidratarea = the hydration

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

So:

• este = is

In this sentence:

• Hidratarea este importantă = Hydration is important

Romanian also very often uses the shorter spoken form e:

• Hidratarea e importantă

Both are correct. Este is a little fuller and slightly more formal or careful in style.

Because it agrees with hidratarea, which is a feminine singular noun.

In Romanian, adjectives must agree in gender and number.

Here:

• hidratarea = feminine singular
• so the adjective must also be feminine singular: importantă

Compare:

• somnul este important = sleep is important
  (somnul is masculine/neuter singular, so important)

• hidratarea este importantă = hydration is important
  (hidratarea is feminine singular, so importantă)

This agreement is something English speakers often need to get used to, because English adjectives do not change this way.

Because here importantă is not directly describing the noun inside a noun phrase. It is part of the predicate after the verb to be.

Structure:

• Hidratarea = subject
• este = verb
• importantă = predicate adjective

So the pattern is:

• [noun] + [to be] + [adjective]

Just like English:

• Hydration is important

If you put the adjective right next to the noun, as in hidratarea importantă, that would mean the important hydration, which is a different structure and usually would need more context.

Yes, Romanian word order is somewhat flexible.

The neutral, most straightforward order is:

• Hidratarea este importantă.

But you may also hear:

• Este importantă hidratarea.

That version can sound more emphatic, like Hydration is important with extra focus on the idea of importance.

For a learner, the first version is the safest and most neutral one to use.

Yes. That is a very common everyday version.

• Hidratarea este importantă. = a bit more formal/full
• Hidratarea e importantă. = more conversational

Both mean the same thing.

A rough English-friendly pronunciation is:

hee-drah-TA-reh-ah ES-teh eem-por-TAN-tuh

A few helpful notes:

• hi sounds like hee
• dra sounds like drah
• stress in hidratarea is on TA
• este is pronounced roughly ES-teh
• stress in importantă is on TAN
• the Romanian ă sounds like the a in about

So the last word, importantă, ends with that relaxed uh sound: im-por-TAN-tuh.

Yes. Hidratare is a feminine noun, and that is why you get:

• hidratarea for the definite form
• importantă for the feminine adjective

Knowing the noun’s gender is important in Romanian because it affects articles and adjective endings.

No. Romanian normally does not need a subject pronoun here.

You do not say:

• Ea este importantă if you mean hydration is important

That would mean She/it is important, and it would not clearly name the subject.

Romanian usually just says the noun itself:

• Hidratarea este importantă.

That is complete and natural.