Si el museo está a trescientos metros, podemos ir a pie.

Si means if in Spanish. It introduces a condition:

• Si el museo está a trescientos metros = If the museum is three hundred metres away

In this sentence, the speaker is saying that under that condition, going on foot is possible.

A useful warning: si without an accent means if, but sí with an accent means yes.

Spanish uses both ser and estar for to be, but they are used in different situations.

Here, está a trescientos metros refers to location/distance, so Spanish uses estar:

• El museo está a trescientos metros. = The museum is 300 metres away.

You would not normally say es a trescientos metros here.

A simple way to think about it:

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

Literally, it means at three hundred metres, but in natural English we usually say three hundred metres away.

In Spanish, a + distance is a common way to express how far away something is:

• Está a cien metros. = It’s 100 metres away.
• Estamos a dos kilómetros. = We’re two kilometres away.

So a here is part of the normal pattern for talking about distance.

El museo means the museum.

Spanish uses definite articles (el, la, los, las) very regularly, often more than English does. In this sentence, the speaker is referring to a specific museum, so el is needed.

• el museo = the museum
• un museo = a museum

If you said Si un museo está a trescientos metros..., it would sound more general or hypothetical: If a museum is 300 metres away...

Podemos ir means we can go or we are able to go. It expresses possibility.

• podemos = we can
• ir = to go

So:

• podemos ir a pie = we can go on foot

If you said vamos a pie, that would mean we are going on foot or we go on foot, which is more direct and less about possibility.

So the sentence is not saying they are definitely going to walk, only that walking is a reasonable option.

Because poder works like a modal verb, similar to can in English.

The pattern is:

• poder + infinitive

Examples:

• Puedo comer. = I can eat.
• Podemos salir. = We can leave.
• Puedes venir. = You can come.

So:

• podemos ir = we can go

Only poder is conjugated here; ir stays in the infinitive.

A pie is the fixed expression for on foot.

• ir a pie = to go on foot
• venir a pie = to come on foot

You simply have to learn it as an idiom.

Be careful with en pie, because that means standing or upright, not on foot in the sense of walking somewhere:

• Estoy en pie. = I am standing / I am up.

So in this sentence, a pie is the correct expression.

Sometimes yes, but it is not exactly the same in all situations.

• ir a pie = to go by walking, as opposed to by car, bus, etc.
• ir caminando = to go walking / to be walking there

In many contexts they are close:

• Podemos ir a pie.
• Podemos ir caminando.

Both can mean we can walk there, but a pie is often the most natural choice when you are talking about means of transport or whether the place is close enough to walk.

Because Spanish often leaves out subject pronouns when they are not needed.

The verb ending already tells you who the subject is:

• podemos = we can

So (nosotros) podemos is possible, but nosotros is usually omitted unless you want emphasis, contrast, or clarity.

For example:

• Podemos ir a pie. = normal
• Nosotros podemos ir a pie, pero ellos no. = emphasis/contrast

Because this is a real or likely condition in the present.

Pattern:

• Si + present, present

So:

• Si el museo está a trescientos metros, podemos ir a pie.

This means something like: If the museum is 300 metres away, we can walk.

This is a normal pattern for real conditions in Spanish.

Compare it with a more hypothetical pattern:

• Si el museo estuviera a trescientos metros, podríamos ir a pie.
• If the museum were 300 metres away, we could go on foot.

So the original sentence sounds more factual or realistic.

It is standard to put a comma when the if-clause comes first:

• Si el museo está a trescientos metros, podemos ir a pie.

If the order is reversed, the comma is usually not used:

• Podemos ir a pie si el museo está a trescientos metros.

So the comma here is normal and correct.

Yes. Spanish allows both orders:

• Si el museo está a trescientos metros, podemos ir a pie.
• Podemos ir a pie si el museo está a trescientos metros.

Both mean the same thing. The first version puts the condition first, which is often a natural way to present the idea.

Because metros is a masculine plural noun.

In Spanish, cientos agrees in gender with the noun that follows:

• trescientos metros because metro is masculine
• trescientas personas because persona is feminine

So in this sentence:

• trescientos metros = correct

Yes. Metro and metros are standard across the Spanish-speaking world for metre/metres.

The main difference is usually in English:

• In British English: metres
• In American English: meters

But the Spanish word is the same: metros.

The sentence is already perfectly natural. In conversation, a speaker from Spain might also say:

• Si el museo está a 300 metros, podemos ir andando.
• Si está a trescientos metros, podemos ir a pie.

A couple of notes:

• Using the number 300 instead of writing it out is common in everyday writing.
• Ir andando is also very common in Spain for go on foot / walk there.

So your original sentence is correct and natural, and there are just a few common alternatives.