A semana em que começa a primavera sempre me dá mais vontade de caminhar no parque.

Because em que links semana to the clause that describes it.

• a semana = the week
• em que começa a primavera = in which spring begins

So the structure is literally the week in which spring begins.

Portuguese often uses a preposition + que after nouns:

• o dia em que = the day when / the day on which
• a cidade em que = the city where / the city in which
• o momento em que = the moment when

English often drops the preposition or uses when, but Portuguese usually keeps it.

In standard Portuguese, em que is the safer and more natural choice after semana.

So:

• A semana em que começa a primavera = standard and natural

Using quando after a noun like semana may be heard in speech, but it is generally less standard in this kind of sentence.

A good rule:

• after a time noun such as dia, semana, momento, época, prefer em que
• quando works better when it introduces a full clause by itself:
  • Quando começa a primavera, eu... = When spring begins, I...

Both are possible.

• A semana em que começa a primavera
• A semana em que a primavera começa

The version in your sentence sounds very natural. Portuguese often puts the verb before the subject in clauses like this, especially when introducing an event or marking time.

So começa a primavera feels a bit like:

• spring begins
• spring is starting

It is not a special tense or meaning change here, just a common word-order pattern.

In Portuguese, seasons usually take a definite article:

• a primavera
• o verão
• o outono
• o inverno

So Portuguese normally says:

• Gosto da primavera.
• O verão é quente.

English often says just spring, but Portuguese commonly uses the article.

Because Portuguese normally uses the article here.

A semana em que começa a primavera means something like:

• the week when spring begins
• the week in which spring starts

It refers to a specific kind of week, even though the statement is general or habitual. Portuguese uses definite articles more often than English in many cases.

Sempre means always.

Here it tells you that this is a repeated pattern:

• every time that week comes, it always has that effect on the speaker

The placement is also natural:

• sempre me dá mais vontade...

Portuguese adverbs like sempre can sometimes move around:

• A semana em que começa a primavera sempre me dá...
• A semana em que começa a primavera me dá sempre...

But the first version is more natural here.

Me is the object pronoun meaning to me or me, and in Brazilian Portuguese it commonly goes before the verb:

• me dá = gives me / makes me feel

So:

• sempre me dá mais vontade = always gives me more desire / always makes me feel more like

In Brazil, this preverbal position is very common in everyday language:

• me disse
• me chamou
• me deu

You may also learn forms like dá-me, but that is much less common in everyday Brazilian Portuguese.

This is a very common Portuguese pattern.

• dar vontade de + infinitive = to make someone feel like doing something
• me dá vontade de caminhar = it makes me feel like walking / it gives me the urge to walk

With mais:

• me dá mais vontade de caminhar = it makes me feel even more like walking / it gives me more desire to walk

So dar vontade de is often more about a feeling or impulse than a direct decision like I want.

Compare:

• Quero caminhar. = I want to walk.
• Estou com vontade de caminhar. = I feel like walking.
• Isso me dá vontade de caminhar. = That makes me feel like walking.

The comparison is implied.

Mais vontade means more desire or more inclination than usual. The sentence suggests:

• more than on other weeks
• more than I normally feel

Portuguese does this very naturally without spelling out the second part.

So:

• me dá mais vontade de caminhar = makes me want to walk more

Because vontade normally takes de before a verb.

Pattern:

• vontade de + infinitive

Examples:

• vontade de dormir
• vontade de sair
• vontade de comer

So:

• mais vontade de caminhar = more desire to walk

This is just the standard construction.

Both can relate to walking, but caminhar is more specifically to walk in the sense of walking for movement, exercise, or pleasure.

• caminhar no parque = walk in the park
• andar can also mean walk, but it is broader and can mean move around, go, function, or even ride

Examples:

• andar pela cidade = walk/go around the city
• O relógio não anda. = The clock is not working.
• andar de ônibus = go by bus / ride the bus

In this sentence, caminhar sounds very natural because it suggests leisurely or health-related walking.

Because em + o contracts to no.

So:

• em o parque -> no parque

This is a standard contraction in Portuguese:

• em + a = na
• em + os = nos
• em + as = nas

Examples:

• na escola
• nos livros
• nas férias

So caminhar no parque simply means to walk in the park.

Usually no parque sounds like in the park or at the park, often referring to a park that is understood from context or one the speaker typically goes to.

Portuguese often uses the definite article in places where English might be more flexible.

Depending on context, it could mean:

• a specific park the speaker has in mind
• the park as a familiar setting in the speaker’s routine

If you wanted a less specific idea, you might say something like:

• em parques = in parks
• num parque = in a park

But no parque is very natural in this sentence.