Al mediodía pedí un bocadillo de jamón y una tapa de aceitunas en el bar de la plaza.

Al is the contraction of a + el. Since mediodía is a masculine noun, Spanish often uses al mediodía as a fixed expression meaning at noon / at midday.

So:

• a + el = al
• al mediodía = at midday

You may sometimes hear a mediodía, but al mediodía is very common and natural in Spain.

Pedí is the first-person singular preterite of pedir.

The preterite is used for:

• a completed action
• at a specific time in the past

Here, the speaker is talking about one finished action: ordering food at noon. Because the sentence gives a clear time reference, Al mediodía, the preterite fits very well.

Compare:

• pedí = I ordered / I asked for once, as a completed event
• pedía = I was ordering / I used to order, which would suggest an ongoing or habitual action

That is a very common question. Pedir is stem-changing, but the change does not happen in all forms.

In the preterite:

• yo pedí
• tú pediste
• él/ella pidió
• nosotros pedimos
• vosotros pedisteis
• ellos/ellas pidieron

So:

• the yo form is pedí, not pidí
• the e → i change appears only in some third-person forms: pidió, pidieron

This is just the standard preterite pattern for -ir stem-changing verbs like pedir and servir.

The accent mark shows where the stress goes: pe-DÍ.

Without the accent, a word ending in a vowel would normally be stressed on the second-to-last syllable. The accent tells you that this word is stressed on the last syllable instead.

So:

• pedí = stress on -dí

This is also useful because many preterite yo forms of -er and -ir verbs end this way:

• comí
• viví
• pedí

Because the two nouns have different grammatical gender:

• bocadillo is masculine → un bocadillo
• tapa is feminine → una tapa

This affects the article:

• un for masculine singular nouns
• una for feminine singular nouns

It does not necessarily mean anything about real-world gender; it is just how the nouns are classified in Spanish.

In Spain, a bocadillo usually means a sandwich made with bread like a baguette or a roll, not sliced sandwich bread.

So a bocadillo de jamón is typically:

• a long piece of bread
• filled with ham

This is very Spanish. If you said sándwich, many people would imagine sliced bread instead.

A tapa is a small portion of food, often served in a bar. In Spain, tapas are a very common part of eating and social life.

A tapa de aceitunas means a small serving of olives. It is not a full meal-sized dish; it is more like a snack or small plate.

So in this sentence, the person ordered:

• one sandwich
• one small serving of olives

In Spanish, de is very often used to show:

• what something contains
• what type of thing it is
• what it is made of

So:

• bocadillo de jamón = sandwich with/of ham
• tapa de aceitunas = tapa of olives

English often uses noun + noun combinations, such as ham sandwich, but Spanish usually prefers de structures in cases like this.

Other examples:

• vaso de agua = glass of water
• zumo de naranja = orange juice
• bocadillo de queso = cheese sandwich

Because they are being thought of differently.

• jamón is treated as an uncountable food ingredient here, like ham
• aceitunas refers to individual olives, so it is plural

So:

• bocadillo de jamón = a ham sandwich
• tapa de aceitunas = a serving of olives

This is very natural in both Spanish and English. We also say:

• cheese sandwich rather than cheeses sandwich
• but olives because you normally get several of them

En el bar de la plaza means in/at the bar on the square or the bar in the square.

Breaking it down:

• en = in / at
• el bar = the bar
• de la plaza = of the square / on the square / in the square

Here, de la plaza identifies which bar it is: the one associated with the town square or plaza.

In natural English, we often translate it less literally:

• at the bar on the square
• at the square’s bar
• at the bar in the plaza

Because Spanish only makes two mandatory contractions with el:

• a + el = al
• de + el = del

But:

• en + el does not contract

So:

• al mediodía is correct
• en el bar stays separate

You would also get del if the noun were masculine:

• de + el mercado = del mercado

But here it is de la plaza, because plaza is feminine, so there is no contraction.

Yes. Spanish word order is fairly flexible.

This sentence starts with Al mediodía to set the time right away, which sounds natural and clear. But other orders are possible, for example:

• Pedí un bocadillo de jamón y una tapa de aceitunas al mediodía.
• En el bar de la plaza, pedí un bocadillo de jamón y una tapa de aceitunas.

The original version sounds very natural because it introduces:

1. the time
2. the action
3. the food
4. the place

That is a very common way to structure a sentence in Spanish.

Both ideas are connected. The basic meaning of pedir is to ask for, but in a food-and-drink context it usually means to order.

So in this sentence:

• pedí un bocadillo... = I ordered a sandwich...

You could think of it literally as I asked for a sandwich, but in natural English I ordered is usually the best translation in this context.