Mi hermana recogió otra concha y me pidió la pala para decorar mejor el castillo.

Recogió is the preterite form of recoger for él/ella/usted: she picked up / she collected.

In this sentence, the speaker is telling a completed action in the past:

• Mi hermana recogió otra concha = My sister picked up another shell

Spanish often uses the preterite for single completed events in a story, just like English uses picked up or asked.

Here, recoger means to pick up or to collect.

With objects on the ground or at the beach, recoger is very natural:

• recoger una concha = to pick up a shell
• recoger juguetes = to pick up toys
• recoger la ropa = to gather/pick up the clothes

So in this context, recogió otra concha suggests she found a shell and picked it up.

In Spanish, otro / otra already includes the idea of another, so you do not normally add una before it.

So:

• otra concha = another shell

Not:

• una otra concha ❌

This is the normal pattern:

• otro libro = another book
• otra vez = another time / again
• otra persona = another person

In this sentence, concha means shell, especially a seashell.

In Spain, this is a normal and common word for shell.
It is worth knowing that in some Latin American countries, concha can also be vulgar slang, but for Spain and for a beach context, concha is completely natural.

Me means to me or from me, depending on how English expresses the idea.

• pidió = asked for
• me pidió la pala = she asked me for the shovel

Spanish uses an indirect object pronoun here:

• me = to me
• te = to you
• le = to him/her/you
• nos = to us
• os = to you all
• les = to them/you all

So me pidió la pala literally works like she asked me the shovel, but the natural English meaning is she asked me for the shovel.

Very often, yes. Pedir commonly means to ask for, to request, or to order.

Examples:

• pedir agua = to ask for water
• pedir ayuda = to ask for help
• pedir la cuenta = to ask for the bill
• pedir una pizza = to order a pizza

In this sentence:

• me pidió la pala = she asked me for the shovel/spade

Be careful not to confuse it with preguntar, which means to ask a question.

For example:

• Me pidió la pala. = She asked me for the shovel.
• Me preguntó dónde estaba la pala. = She asked me where the shovel was.

Because me is already an object pronoun, so you do not need the preposition a.

Compare:

• Me pidió la pala. = She asked me for the shovel.
• Pidió la pala a su hermano. = She asked her brother for the shovel.

When you use a full noun, Spanish often uses a:

• pidió la pala a su hermano

When you use the pronoun, you just use:

• me
• te
• le, etc.

You can also add the full phrase for emphasis:

• Me pidió la pala a mí. But that is only for emphasis or contrast, not the neutral version.

La pala uses the definite article because it refers to a specific shovel/spade that both people can identify from the situation.

At the beach, this probably means the shovel they were already using or the one nearby.

Compare:

• me pidió la pala = she asked me for the shovel
• me pidió una pala = she asked me for a shovel, any shovel

Spanish uses the definite article quite often when the object is clear from context.

Pala can mean shovel, spade, or a small digging tool, depending on context.

At the beach, la pala most likely means a toy shovel/spade used for sand.
So in natural English, you might translate it as:

• the shovel
• the spade
• even the little shovel, depending on context

Because the most natural word order in modern Spanish is:

• para + infinitive
• then the adverb

So:

• para decorar mejor el castillo = to decorate the castle better

This is the normal, everyday order:

• para hacerlo mejor
• para entender mejor
• para trabajar mejor

You may sometimes see mejor before the infinitive in more literary or formal styles, but decorar mejor is the normal choice here.

Because mejor already means better.

It is the comparative form of bien:

• bien = well
• mejor = better

So:

• decorar mejor = to decorate better

You do not say:

• más mejor ❌

Just as in English you say better, not more better.

Yes. Para + infinitive often expresses purpose: in order to, so as to, or simply to.

So:

• me pidió la pala para decorar mejor el castillo means
• she asked me for the shovel to decorate the castle better

Other examples:

• Estudio para aprender. = I study to learn.
• Compró pintura para arreglar la pared. = He bought paint to fix the wall.
• Usó una cuchara para mezclar. = She used a spoon to stir.

Grammatically, el castillo simply means the castle, but in this beach context it almost certainly means a sandcastle.

Spanish often leaves out de arena when the context is obvious.

So:

• el castillo here = the sandcastle

If someone wanted to be fully explicit, they could say:

• el castillo de arena

Yes, that is a fairly literal translation, and it helps show the structure.

But more natural English would usually be:

• My sister picked up another shell and asked me for the shovel so she could decorate the sandcastle better.

The Spanish sentence is a bit more compact than the most natural English version, which is very common.

Because the sentence is narrating two completed past actions in sequence:

1. Mi hermana recogió otra concha
2. y me pidió la pala

So the story is:

• she picked up another shell
• and then she asked me for the shovel

Spanish often uses the preterite like this when telling a series of events:

• Entró, miró, sonrió y se fue. = He came in, looked, smiled, and left.

This sentence follows that same storytelling pattern.