Gura este deschisă.

Because gura is the form with the definite article attached, and in Romanian the definite article usually goes at the end of the noun.

• gură = a mouth
• gura = the mouth

So Gura este deschisă means The mouth is open, not just Mouth is open.

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

So here:

• gura = the mouth
• este = is
• deschisă = open

Together: The mouth is open.

In standard Romanian, when making a normal present-tense sentence like this, este is usually kept:

• Gura este deschisă. = The mouth is open.

In casual speech, Romanian speakers may sometimes omit forms of to be, especially in certain informal contexts, but for learners it is best to use este here.

Because the adjective has to agree with the noun.

Gura is:

• singular
• feminine
• definite

So the adjective takes the feminine singular form:

• masculine singular: deschis
• feminine singular: deschisă

That is why we say gura este deschisă.

You usually learn the gender together with the noun. Gură is a feminine noun.

One clue is the definite form:

• gură → gura

That -a definite ending is very common with feminine singular nouns.

Because it is feminine, adjectives also use feminine forms with it:

• gura mică = the small mouth
• gura deschisă = the open mouth

A simple pronunciation guide is:

• gura ≈ GOO-rah

More precisely:

• gu sounds like goo
• ra has a tapped or rolled r, not the English r

So it is not like English gurr-uh. It is closer to GOO-ra.

A rough guide is:

• deschisă ≈ dess-KEE-suh

A bit more carefully:

• des = like dess
• chi = like kee
• să = a short unstressed sound ending with ă

The letter combination ch before i sounds like k, so deschisă is not pronounced with English ch as in chair.

Ă is a very common Romanian vowel. It is a short, central vowel, similar to the a sound in English sofa or about.

In this sentence, you hear it in:

• gură
• deschisă

It is not the same as a full a sound like in father.

In Romanian, adjectives can appear in different positions, but the usual neutral position is after the noun.

So:

• gura deschisă = the open mouth

With este, the adjective is part of the predicate:

• Gura este deschisă. = The mouth is open.

That word order is completely normal.

By itself, Gura este deschisă most directly means The mouth is open.

Depending on context, English might translate it as:

• The mouth is open
• His mouth is open
• Her mouth is open
• Your mouth is open

Romanian often leaves possession unspoken if the context makes it obvious. But if you want to be explicit, you can say:

• Gura lui este deschisă. = His mouth is open.
• Gura ei este deschisă. = Her mouth is open.

It comes from the verb a deschide = to open, so literally it is related to opened/open.

In actual usage, deschis / deschisă often means simply open:

• ușa este deschisă = the door is open
• gura este deschisă = the mouth is open

So although it historically matches opened, in normal English translation open is usually the best choice.

Yes. E is a common short form of este in everyday Romanian.

So both are correct:

• Gura este deschisă. — more full/neutral
• Gura e deschisă. — very common in speech

Learners should understand both.

Only that it is the first word of the sentence, so it is capitalized.

The noun itself is normally written lowercase unless it begins a sentence:

• Gura este deschisă.
• Am văzut gura. = I saw the mouth.