El muelle, desde donde salimos, está vacío.

Here muelle means pier, dock, or quay — a structure by the water where boats leave from or arrive.

It does not mean spring, even though muelle can also mean that in other contexts. Spanish often has words with more than one meaning, and the context tells you which one is intended.

Also, muelle is masculine, so it takes el:

• el muelle
• el muelle está vacío

In Spanish, it is very common to use the definite article where English might not, especially when talking about a specific thing already identified in the situation.

So El muelle means the pier/dock. Without the article, muelle would sound incomplete or more like a dictionary form.

Compare:

• El muelle está vacío. = The pier is empty.
• Un muelle está vacío. = A pier is empty.

The commas show that desde donde salimos is extra information about el muelle. This is a non-restrictive relative clause.

The speaker is talking about a specific pier, and then adds a comment about it:

• El muelle ... está vacío.
• desde donde salimos = extra detail about that pier

In English, this is similar to:

• The pier, from where we left, is empty.

If there were no commas, it would sound more like the clause is identifying which pier:

• El muelle desde donde salimos está vacío.

That version is possible, but it feels more restrictive: the pier that we left from.

Because the idea is from where.

• donde = where
• desde donde = from where

The verb salir often involves a point of origin, so desde fits naturally:

• Salimos desde el muelle. = We left from the pier.
• El muelle, desde donde salimos... = The pier, from where we left...

If you said just donde, the meaning would shift more toward simple location rather than origin.

Because here donde is a relative word, not a question word.

Spanish uses the accented forms when they are interrogative or exclamatory:

• ¿Dónde salimos? = Where did we leave from?
• No sé dónde salimos. = I don’t know where we left from.

But in a relative clause like this, there is no accent:

• El muelle desde donde salimos...

So:

• donde = relative where
• dónde = interrogative/exclamatory where

Salimos can be either:

1. present tense: we leave
2. preterite: we left

So by itself, salimos is ambiguous.

In this sentence, most learners will naturally understand it as we left, because it refers to a departure from that pier. But context would decide for sure.

Examples:

• Salimos ahora. = We’re leaving now. / We leave now.
• Ayer salimos del muelle. = Yesterday we left the pier.

So in El muelle, desde donde salimos, está vacío, the most likely reading is:

• The pier, from where we left, is empty.

Yes, both are possible, but they are slightly different in feel.

Possible versions:

• El muelle, desde donde salimos, está vacío.
• El muelle, del que salimos, está vacío.
• El muelle, desde el que salimos, está vacío.

Notes:

• desde donde sounds very natural when referring to a place.
• desde el que is also correct and a bit more explicit.
• del que is possible, but with salir many speakers may prefer desde donde or desde el que when emphasizing the point of departure.

So desde donde is a very idiomatic choice here.

Because vacío here describes a state or condition, not an essential characteristic.

Spanish often uses:

• estar for states, conditions, results
• ser for identity, classification, essential description

So:

• El muelle está vacío. = The pier is empty.

That means it is empty at the moment or in the relevant situation.

Using es vacío would sound unnatural here, because a pier is not inherently defined by being empty.

Yes. Vacío is an adjective, so it agrees in gender and number with muelle.

Since muelle is:

• masculine
• singular

the adjective is:

• vacío

Compare:

• El muelle está vacío.
• La playa está vacía.
• Los muelles están vacíos.
• Las playas están vacías.

Yes. Spanish allows some flexibility.

For example:

• El muelle, desde donde salimos, está vacío.
• El muelle está vacío; salimos de allí.
• Está vacío el muelle desde donde salimos.
  This is possible, but less neutral.

The original version is very natural because it introduces the place first, adds the descriptive clause, and then gives the main statement.

It sounds slightly more careful or written because of desde donde and the embedded relative clause.

In casual speech, many people might say something simpler, such as:

• El muelle del que salimos está vacío.
• El muelle de donde salimos está vacío.
• El muelle desde el que salimos está vacío.

The original sentence is still perfectly correct and natural, especially in more descriptive or formal language.

Because it interrupts the main sentence to add extra information about el muelle.

The basic sentence is:

• El muelle está vacío.

Then the speaker inserts:

• desde donde salimos

So the full structure is:

• El muelle,
  • extra information + , está vacío.

This is common in both Spanish and English when adding a non-essential detail:

• The pier, from where we left, is empty.

It helps the listener identify or remember which pier is being talked about, while keeping the main message as it is empty.