El supermercado está justo al lado de la farmacia.

Spanish articles agree with the gender of the noun.

• el supermercado because supermercado is masculine
• la farmacia because farmacia is feminine

This is grammatical gender, not biological sex. In Spanish, nouns are normally learned together with their article, so it is best to remember el supermercado and la farmacia as full chunks.

Spanish has two main verbs for to be: ser and estar.

Here, estar is used because the sentence is talking about location:

• El supermercado está... = the supermarket is located...

A useful rule for learners is:

• ser = identity, description, origin, etc.
• estar = location, condition, temporary states

So for places and where things are, Spanish usually uses estar:

• Madrid está en España.
• La farmacia está cerca.

The accent mark shows which syllable is stressed: es-TÁ.

It also helps distinguish forms in writing. In this case, está is the he/she/it is or you are form of estar.

Without the accent, esta is a different word:

• esta = this
• está = is

So the accent is important both for pronunciation and meaning.

Here, justo adds emphasis. It means something like:

• right
• exactly

So justo al lado de means right next to or exactly next to.

Without justo, the sentence would still be correct:

• El supermercado está al lado de la farmacia.

That simply sounds a little less emphatic.

Al lado de is a fixed expression meaning:

• next to
• beside
• at the side of

It is very common in everyday Spanish.

Examples:

• El banco está al lado del hotel.
• Mi casa está al lado de un parque.

It is often one of the first location phrases learners meet.

Because the full expression is al lado de, not a lado de.

Also, al is a contraction of:

• a + el = al

Historically and grammatically, the phrase includes el:

• al lado = at the side

So you should learn al lado de as one complete expression.

The de is part of the expression al lado de.

So the structure is:

• al lado de + noun

Examples:

• al lado de la farmacia
• al lado del supermercado
• al lado de mi casa

In English, we say next to the pharmacy. In Spanish, the preposition de is required after al lado.

Because Spanish only contracts de + el into del.

So:

• de + el supermercado → del supermercado
• de + la farmacia stays de la farmacia

There is no contraction with la.

Compare:

• Está al lado del banco.
• Está al lado de la farmacia.

Yes, sometimes.

This sentence has the normal, very natural order:

• El supermercado está justo al lado de la farmacia.

But you could also say:

• Justo al lado de la farmacia está el supermercado.

That version sounds more marked or descriptive, as if you are pointing it out or giving directions in a more dramatic way.

You could also reverse the relationship:

• La farmacia está justo al lado del supermercado.

That means the same location relationship, just from the pharmacy’s point of view.

Usually no, not in this sentence.

Spanish normally uses the article with places like:

• el supermercado
• la farmacia
• el banco
• la estación

So Está justo al lado de farmacia would usually sound incomplete or unnatural in standard Spanish.

In general, when talking about a specific place or building, keep the article.

In Spain, the j in justo is pronounced like a strong throaty sound, not like the English j in job.

A rough guide:

• justo ≈ HOOS-toh, but with a harsher h sound

The stress is on the first syllable:

• JUS-to

So do not pronounce it like joos-to with an English j sound.

In most of Spain, the c before i is pronounced like the th in think.

So farmacia is roughly:

• far-MA-thia

In many parts of Latin America, it would sound more like:

• far-MA-sia

Since you asked about Spanish from Spain, the th-like pronunciation is the usual one to learn.

Yes, but the meaning changes slightly.

• junto a = next to / beside
• cerca de = near

So:

• El supermercado está junto a la farmacia.
  Very close, basically next to it.

• El supermercado está cerca de la farmacia.
  Near the pharmacy, but not necessarily immediately beside it.

Al lado de and junto a are often very similar. Cerca de is less exact.

Yes, completely natural.

El supermercado está justo al lado de la farmacia sounds like normal spoken and written Spanish in Spain. It is exactly the kind of sentence you would hear when someone is giving directions or describing where a place is.