A veces las raíces salen de la maceta y ensucian el suelo del balcón.

A veces means sometimes. It is the most common, neutral way to say that.

You can also say Algunas veces, and it means basically the same thing, but A veces is shorter and more natural in everyday speech.

So in this sentence, A veces is the most idiomatic choice.

Spanish uses the definite article much more often than English.

Here, las raíces sounds natural because we are talking about the roots in a general-but-concrete way: the roots of the plant in that pot. In English, you might simply say roots, but Spanish often prefers the roots in this kind of sentence.

So las raíces is not unusually specific; it is just normal Spanish usage.

The singular is la raíz. When a noun ends in -z, the z changes to c before -es in the plural:

• raíz → raíces
• luz → luces
• pez → peces

This is a spelling rule in Spanish. It keeps the pronunciation natural before e.

In Spain, raíces is pronounced approximately ra-EE-thes in most regions.

The accent mark on í shows that a and í are pronounced in separate syllables:

• ra-í-ces

Without that accent, Spanish readers might try to combine the vowels more.

So the written accent helps show the correct stress and syllable division.

Salen is the third-person plural present form of salir.

It matches the subject las raíces, which is plural:

• la raíz sale
• las raíces salen

So the verb ends in -n because the subject is plural.

In Spanish, the present tense is often used for habitual or repeated actions, not only for things happening at this exact moment.

Because the sentence starts with A veces, it means this happens from time to time. So the present tense is perfect:

• salen
• ensucian

This is like English using the present simple in Sometimes the roots come out...

The verb salir normally goes with de when you say where something comes out from:

• salir de casa
• salir del coche
• salir de la maceta

So salir de means to come/go out of, to emerge from.

In this sentence, the roots are coming out from the pot, so de la maceta is exactly what Spanish needs.

Because de + el contracts to del in Spanish:

• de + el balcón → del balcón

But there is no contraction with la:

• de + la maceta → de la maceta

So:

• de la maceta is correct
• del balcón is correct
• de el balcón would be wrong here

Because ensuciar here is being used as a transitive verb: the roots make something else dirty.

• Las raíces ensucian el suelo = the roots dirty the floor

If you said se ensucian, that would usually mean they get dirty themselves.

So the version in the sentence means:

• the roots are causing the floor to become dirty

not

• the roots themselves are becoming dirty

Because the same subject continues after y:

• Las raíces salen de la maceta y ensucian el suelo...

Spanish does not need to repeat the subject if it is still the same. English works similarly:

• The roots come out of the pot and dirty the floor

Repeating las raíces would be possible for emphasis, but it would sound less natural in a normal sentence.

Because el balcón is the whole balcony, while el suelo del balcón is specifically the floor/surface of the balcony.

The sentence wants to be precise: the roots are making the floor dirty, not the entire balcony in a general sense.

So el suelo del balcón is more exact.

In Spain, suelo is the most natural word for the physical floor/ground surface.

Piso can sometimes mean floor, but in Spain it very often means apartment. Because of that, el suelo del balcón is clearer and more natural here.

So for this sentence, suelo is the better choice.