Los gorriones revolotean sobre el agua.

Los is the masculine plural definite article, meaning the.

So los gorriones = the sparrows.

Spanish usually uses the definite article more often than English does, especially when talking about a whole group or some known things in context.

• el = the, masculine singular
• la = the, feminine singular
• los = the, masculine plural
• las = the, feminine plural

Because gorriones is plural, the article also has to be plural: los.

The singular is gorrión = sparrow.

So:

• el gorrión = the sparrow
• los gorriones = the sparrows

Notice the spelling change:

• singular: gorrión
• plural: gorriones

The written accent disappears in the plural because the stress pattern changes naturally in Spanish pronunciation.

Because the subject is plural: Los gorriones = the sparrows.

In Spanish, the verb has to agree with the subject.

• el gorrión revolotea = the sparrow flutters
• los gorriones revolotean = the sparrows flutter

So revolotean is the third person plural form of the verb.

The infinitive is revolotear.

Revolotean is the present tense form for they:

• yo revoloteo = I flutter
• tú revoloteas = you flutter
• él/ella revolotea = he/she flutters
• ellos/ellas revolotean = they flutter

In this sentence, revolotean means something like flutter, flit about, or fly around lightly.

Volar is the general verb to fly.

Revolotear is more specific. It suggests light, repeated, restless movement in the air: fluttering, flitting about, hovering around, or flying around in small movements.

So:

• Los pájaros vuelan = The birds fly
• Los gorriones revolotean = The sparrows flutter/flit about

In your sentence, revolotean gives a more vivid image than vuelan.

Because Spanish often leaves out subject pronouns when they are not needed.

The verb ending already shows who is doing the action:

• revolotean already tells you it is they

So Spanish does not need to say ellos unless there is special emphasis or contrast.

• Los gorriones revolotean sobre el agua. = normal, natural
• Ellos revolotean sobre el agua. = They flutter over the water, with extra emphasis

This is called a pro-drop language feature.

This is a very common question.

Agua is indeed a feminine noun. But in the singular, Spanish uses el instead of la before some feminine nouns that begin with a stressed a sound, to make pronunciation easier.

So you say:

• el agua
• el águila
• el alma

But the noun is still feminine. You can see that in adjectives:

• el agua fría = the cold water
• el águila blanca = the white eagle

The adjective stays feminine: fría, blanca.

In the plural, the normal feminine article returns:

• las aguas
• las águilas

So in your sentence, el agua is correct even though agua is feminine.

Because sobre means over, above, or sometimes on.

So:

• sobre el agua = over the water
• en el agua = in the water

If the sparrows are flying above the surface, sobre el agua is the right choice.

Compare:

• Los gorriones revolotean sobre el agua. = The sparrows flutter over the water.
• Los peces nadan en el agua. = The fish swim in the water.

Because Spanish only has two standard contractions with el:

• a + el = al
• de + el = del

So:

• voy al parque = I go to the park
• vengo del parque = I come from the park

But with sobre, there is no contraction:

• sobre el agua — correct
• not sobrel agua

So the sentence keeps the two words separate: sobre el agua.

A rough pronunciation is:

go-RRYO-nes

A few key points:

• The g in gorrión is a hard g, like in go
• The rr is a rolled or trilled r
• io in -riones flows together smoothly
• In the plural gorriones, the stress falls naturally on -o-: go-RRYO-nes

The singular gorrión is stressed on the last syllable, which is why it has a written accent:

• go-rrión

Yes, Spanish word order is flexible, although the original version is the most neutral and natural:

• Los gorriones revolotean sobre el agua.

You could also hear:

• Sobre el agua revolotean los gorriones.

That version puts more focus on sobre el agua or sounds a bit more literary or descriptive.

So the basic meaning stays the same, but the emphasis can change depending on word order.