Subimos al ferri, desde donde vemos el muelle.

Subimos is the 1st person plural of subir in the present tense: we go up / we get on / we board.

With transport, Spanish often uses subir a to mean to get onto / board something:

• Subimos al tren = We get on the train
• Subimos al barco = We get on the boat
• Subimos al ferri = We get on the ferry

Even though subir literally means to go up, in this kind of context it is the normal verb for boarding.

Because a + el = al.

This contraction is mandatory in Spanish.

• a el barco → al barco
• a el ferri → al ferri

So Subimos al ferri means We get onto the ferry.

One useful exception: this contraction does not happen if El is part of a proper name.

• Voy a El Escorial ✅
• not Voy al Escorial in that specific proper-name sense

Both forms may be seen, but ferry is very common in real usage because it is the original English borrowing.
Ferri is a more hispanicised spelling.

So:

• el ferry = very common
• el ferri = adapted spelling, also understandable

A learner should definitely recognise both. In Spain, many speakers would naturally write ferry.

Because Spanish usually drops subject pronouns when they are not needed.

The ending -imos already tells you the subject is we:

• subimos = we get on / we got on (depending on context)
• vemos = we see

So Nosotros subimos al ferri is grammatically possible, but usually unnecessary unless you want emphasis or contrast:

• Nosotros subimos al ferri, pero ellos no.
  We got on the ferry, but they didn’t.

Desde donde means from where or from which place.

In this sentence, it refers back to the ferry:

• Subimos al ferri, desde donde vemos el muelle.
• We get on the ferry, from where we can see the pier.

It introduces the place from which the action of seeing happens.

You can think of it like this:

• donde = where
• desde donde = from where

So the ferry is the location from which the speaker sees the pier.

Yes. These are more explicit relative structures.

For example:

• Subimos al ferri, desde el que vemos el muelle.
• Subimos al ferri, desde el cual vemos el muelle.

All of these are possible, but they differ a bit in tone:

• desde donde = very natural and straightforward for places
• desde el que = also natural
• desde el cual = more formal or written

With a place-like noun such as ferri, desde donde sounds very natural.

Because the sentence is presented in the present: we get on the ferry, from where we see the pier.

Spanish often uses the present tense for:

• things happening now
• habitual actions
• narrative description

So vemos simply matches the tense of subimos.

Depending on context, English might translate it in slightly different ways:

• We get on the ferry, from where we see the pier
• We board the ferry, from where we can see the pier
• We’re getting on the ferry, from where we can see the pier

Yes, subimos can be either:

• present indicative: we go up / we get on
• preterite: we went up / we got on

The form is the same. Only the context tells you which one is meant.

For example:

• Ahora subimos al ferri. = Now we’re getting on the ferry.
• Ayer subimos al ferri. = Yesterday we got on the ferry.

So if you saw this sentence by itself, there is some ambiguity in form, though context usually makes it clear.

Muelle usually means pier, dock, or quay, depending on context.

It is the structure by the water where boats or ferries stop.

Related words:

• puerto = port/harbour
• embarcadero = landing stage / small pier
• muelle = dock/pier/quay

So in this sentence, vemos el muelle means we see the pier/dock.

The comma marks an added relative clause giving extra information.

The basic idea is:

• Subimos al ferri = main clause
• desde donde vemos el muelle = additional descriptive information

This kind of pause is natural in Spanish when the second part comments on or describes the previous noun or situation.

Without getting too technical, the comma helps show that the sentence is not restricting which ferry, but adding information about it.

Yes, exactly.

Spanish often treats vehicles or locations as the point from which something is seen or done:

• Desde el tren vemos el campo. = From the train we see the countryside.
• Desde la ventana veo la calle. = From the window I see the street.
• Desde donde estamos, vemos el mar. = From where we are, we can see the sea.

So here the ferry is the vantage point: once on it, we see the pier from there.