Cuando hace fresco, me gusta caminar en la playa.

Because this sentence describes a habitual situation: Whenever it’s cool, I like to walk on/at the beach.

In Spanish, when cuando refers to something that happens regularly or generally, you use the indicative:

• Cuando hace fresco, me gusta caminar...

If you are talking about a future situation, Spanish usually uses the subjunctive:

• Cuando haga fresco, iremos a la playa.
  • When it’s cool, we’ll go to the beach.

So here, hace is correct because the sentence is about a general habit.

This is a very common weather expression in Spanish. For weather, Spanish often uses hacer instead of to be.

Examples:

• Hace calor = It’s hot
• Hace frío = It’s cold
• Hace fresco = It’s cool / It’s pleasantly chilly
• Hace sol = It’s sunny
• Hace viento = It’s windy

So even though English says it is cool, Spanish says it makes coolness, in a way. It’s just an idiomatic pattern you learn as a set expression.

Here, fresco means cool in the weather sense: not hot, and usually not seriously cold either.

In Spain, hace fresco often suggests:

• a mild coolness
• fresh air
• a comfortable temperature for walking

It can sometimes feel a bit chilly depending on context, but it is usually softer than hace frío.

Also, fresco can mean other things in other contexts, such as:

• fresh food
• fresh air
• even cheeky or brazen when talking about a person

But in this sentence, it clearly means the weather is cool.

Because gustar works differently from to like in English.

A helpful literal way to think about it is:

• Me gusta caminar = Walking is pleasing to me

So:

• me = to me
• gusta = is pleasing
• caminar = walking / to walk

The thing being liked is caminar, and that is treated as the subject of the verb.

That’s why yo gusto caminar is not how Spanish expresses this idea.
Gustar is not normally used like English like.

Because the subject of the verb is caminar, and an infinitive counts as singular.

So:

• Me gusta caminar. = I like walking.
• Me gusta nadar. = I like swimming.

But if the thing you like is plural, then you use gustan:

• Me gustan las playas tranquilas. = I like quiet beaches.

So the rule is:

• gusta with one thing or an infinitive
• gustan with plural nouns

After gustar, Spanish usually uses the infinitive to talk about liking an action in general.

So:

• Me gusta caminar = I like walking
• Me gusta leer = I like reading
• Me gusta viajar = I like travelling

In English, we often use the -ing form, but Spanish uses the infinitive for this kind of general action.

So caminar here means to walk / walking.

Yes, and the choice changes the nuance.

• en la playa = at/on the beach
  • focuses on the location
• por la playa = along/around the beach
  • focuses more on movement through that area
• a la playa = to the beach
  • indicates destination

So:

• Me gusta caminar en la playa = I like walking at/on the beach
• Me gusta caminar por la playa = I like walking along the beach
• Me gusta caminar a la playa would usually mean I like walking to the beach, which is a different idea

In everyday Spanish, many native speakers might prefer por la playa if they want to emphasize walking along the shore. But en la playa is still perfectly understandable and natural as a general location.

Yes, often you can, but the nuance is slightly different.

• caminar = to walk
• pasear = to stroll / to go for a walk
• andar = to walk / to go around, depending on context

So:

• Me gusta caminar en la playa = I like walking on the beach
• Me gusta pasear por la playa = I like strolling along the beach

Pasear often sounds a bit more leisurely and relaxed, which fits a beach context very well.
So a native speaker might very naturally say:

• Cuando hace fresco, me gusta pasear por la playa.

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

In:

• me gusta

the sentence already makes it clear that the feeling is mine because of me.

Adding yo is possible, but it usually adds emphasis or contrast:

• A mí me gusta caminar en la playa, pero a él no.
  • I like walking on the beach, but he doesn’t.

So the version without yo is the normal, natural one.

Because the sentence begins with a subordinate clause, followed by the main clause.

Structure:

• Cuando hace fresco, = subordinate time clause
• me gusta caminar en la playa. = main clause

In Spanish, it is normal to put a comma after an introductory clause like this, especially when it comes first.

Compare:

• Cuando hace fresco, me gusta caminar en la playa.
• Me gusta caminar en la playa cuando hace fresco.

Both are correct, but when the cuando clause comes first, the comma is standard and helps readability.