En ville, on prend souvent le métro pour aller au travail.

En ville is a very common French expression meaning something like in town or in the city as a general setting.

In this sentence, En ville sets the scene: it means when you’re in the city / in an urban environment.

• En ville = a general, idiomatic expression
• Dans la ville = more literal, like inside the city

So En ville sounds much more natural here.

The comma helps mark it as an introductory phrase, but the main idea is that en ville is the standard expression for this kind of statement.

In modern French, on is very often used where English would say we.

So although on can literally mean one or people in general, in everyday French it very commonly replaces nous.

Here, on prend souvent le métro can mean:

• we often take the metro
• people often take the metro
• you often take the metro in a general sense

Because the sentence is a general statement about city life, on works very naturally.

A key grammar point:

• on takes third-person singular verb forms

So:

• on prend not
• on prenons

French commonly uses prendre with means of transport:

• prendre le métro
• prendre le bus
• prendre le train
• prendre la voiture

So prendre le métro is the normal way to say to take the metro.

Even though the whole sentence is about going to work, French expresses the transport choice with prendre, not with a verb meaning go by in this structure.

Souvent is an adverb of frequency, meaning often.

In French, adverbs like souvent, toujours, and parfois are often placed after the conjugated verb in a simple tense.

So:

• on prend souvent le métro

This is the most neutral and natural word order.

English often puts often before the main verb:

• we often take the metro

French usually does not do that in this kind of sentence.

French usually uses an article where English often does not.

So French says:

• prendre le métro
• prendre le bus
• prendre le train

Even though English says:

• take the metro
• take the bus
• take the train

the article is still required in French.

Here, le métro refers to the metro system in a general sense, not one specific train.

Pour + infinitive is a very common French structure used to express purpose.

So:

• pour aller au travail = to go to work / in order to go to work

The infinitive aller is used because the subject is the same as in the main clause:

• on prend souvent le métro
• on is also the one who goes to work

This is exactly like English using to + verb for purpose.

Because à + le contracts to au in French.

So:

• à + le = au

That means:

• aller au travail comes from
• aller à le travail which is not allowed as a separate form

This contraction is mandatory.

You should also remember:

• à + les = aux

So au travail is simply the correct contracted form.

This is one of those places where French and English do not match directly.

English says:

• go to work

French says:

• aller au travail

French normally uses the article here as part of the fixed expression. So even though English has no article before work, French uses le, which becomes au after à.

So it is best to learn aller au travail as a chunk.

The comma is not absolutely necessary, but it is very natural.

It shows that En ville is an introductory phrase setting the context before the main clause:

• En ville, on prend souvent le métro...

Without the comma, the sentence would still be understandable:

• En ville on prend souvent le métro pour aller au travail.

But the comma makes the structure clearer and slightly smoother in writing.

Most likely, it is a general statement about city life.

Because it uses on, the sentence sounds like:

• people often take the metro to go to work in the city or
• we often take the metro to go to work in the city

So the exact English equivalent depends on context, but grammatically and stylistically, French often uses on for broad, everyday statements like this.