Guarda la ropa sucia en el cesto antes de ducharte.

Because guarda here is the tú imperative (the informal singular command) of guardar.

• guardar = to put away / to store / to keep
• guardas = you keep / you store (present tense)
• guarda = put away! / store! (command)

So Guarda la ropa sucia... means Put the dirty clothes away... or Put the dirty laundry...

In Spanish, ropa is usually treated as a singular collective noun. Even though it refers to clothing in general, grammatically it is singular.

So:

• la ropa = the clothes / the clothing
• la ropa sucia = the dirty clothes / the dirty laundry

That is why you get:

• la, not las
• sucia, not sucias

It can mean either, depending on context.

In this sentence, because you are being told to put it in a basket before showering, dirty laundry is a very natural English translation.

So:

• la ropa sucia = dirty clothes
• in context, often = dirty laundry

Spanish often uses the same phrase where English might choose one wording or the other.

Because en emphasizes being inside the basket.

• en el cesto = in the basket
• al cesto literally suggests movement to the basket

With verbs like guardar, Spanish normally uses en because the idea is put it away in the basket, not just toward the basket.

So Guarda la ropa sucia en el cesto sounds natural because the final location matters.

Cesto means basket or hamper, depending on context.

Both cesto and cesta exist in Spanish. The difference is mostly grammatical gender and sometimes regional or lexical preference, not a big meaning change in many everyday contexts.

Here:

• el cesto = the basket / the hamper

In this sentence, it most likely means a laundry basket or clothes hamper.

After antes de, Spanish uses an infinitive when the subject stays the same.

So:

• antes de ducharte = before showering / before you shower

Here, ducharte is made of:

• duchar = to shower
• te = yourself / you

So literally it is something like before showering yourself.

You do not say antes de te duchas because te duchas is a conjugated verb form, and that structure does not work after antes de.

Compare:

• Antes de salir, cierra la puerta. = Before leaving, close the door.
• Antes de acostarte, apaga la luz. = Before going to bed, turn off the light.

Because ducharse is a reflexive verb: to shower oneself.

The infinitive is:

• ducharse = to shower / to take a shower

When Spanish adds another word before it, the reflexive pronoun changes according to the person:

• ducharme = for me to shower
• ducharte = for you to shower
• ducharse = for him/her/you(formal) to shower

Since the sentence is giving a command to tú, it uses ducharte:

• antes de ducharte = before you shower

Yes, but the nuance changes a little.

• pon la ropa sucia en el cesto = put the dirty clothes in the basket
• guarda la ropa sucia en el cesto = put away / place the dirty clothes in the basket

Pon focuses more directly on the action of putting something somewhere. Guarda often suggests putting it where it belongs or putting it away neatly.

In this context, both are possible, but guarda sounds a bit more like an instruction about proper tidying or routine.

In modern everyday Spanish, ducharse normally means to shower or to take a shower.

It comes from ducha = shower.

So:

• ducharte = to shower / for you to shower

If Spanish wanted to say wash yourself more generally, it would more likely use lavarte.

Spanish often leaves out subject pronouns when they are clear from the verb form or context.

Here, guarda already tells you the subject is an informal singular you (tú).

So:

• Guarda la ropa sucia... = Put the dirty laundry away...
• Tú guarda la ropa sucia... is possible, but it would sound more emphatic or contrastive.

Omitting the subject pronoun is normal Spanish.

It is informal singular, because of guarda and ducharte.

That means it is addressed to:

• tú = you (informal, singular)

A formal version would be:

• Guarde la ropa sucia en el cesto antes de ducharse.

And a plural informal version in Spain would be:

• Guardad la ropa sucia en el cesto antes de ducharos.

So the original sentence is clearly speaking to one person informally.

Yes. That is a very natural way to understand it in English.

Spanish often uses a reflexive verb where English can choose among several translations:

• antes de ducharte = before you shower
• before showering
• before taking a shower

All of these work well in English, depending on style and context.