Même en été, je prends un sac de couchage léger, parce que les nuits sont fraîches près de la mer.

Même en été means even in summer.

• même = even
• en été = in summer

Putting it at the beginning gives emphasis: Even in summer, ...

You could also say:

• Je prends un sac de couchage léger même en été.

That is still correct, but starting with Même en été highlights the surprising idea first.

In French, seasons are usually used with en:

• en été = in summer
• en hiver = in winter
• en automne = in autumn
• often au printemps = in spring

So en été is the normal way to say in summer.

Dans l’été is much less common and would usually mean something more specific, like during the summer period in a particular context, not the general season.

Yes, je prends literally means I take, from the verb prendre.

In French, prendre is often used where English might say:

• I take
• I bring
• I pack
• I carry

So in this sentence, je prends un sac de couchage léger means something like:

• I take a light sleeping bag
• I bring a light sleeping bag
• I pack a light sleeping bag

All of those are natural translations depending on context.

Prends is pronounced roughly like pran (with a nasal vowel), not like every final consonant is fully sounded.

A few useful points:

• prendre = the infinitive
• je prends
• tu prends
• il/elle prend

In prends, the final d is normally silent. The s is also not pronounced by itself.

So je prends sounds approximately like zhuh pran.

This is normal in French: many final consonants are not pronounced unless there is a liaison in a different context.

Un sac de couchage is the normal French expression for a sleeping bag.

Literally, it is:

• un sac = a bag
• de couchage = for sleeping / of sleeping

So the full phrase is an idiomatic noun expression, not something you would usually translate word-for-word.

French often builds nouns this way:

• une salle de bain = bathroom
• une brosse à dents = toothbrush
• un sac de couchage = sleeping bag

In French, many adjectives come after the noun.

So:

• un sac léger = a light bag
• un sac de couchage léger = a light sleeping bag

This is the normal order here.

Some adjectives often come before the noun, but léger usually comes after it when it describes physical weight.

So French says:

• un sac de couchage léger

not usually:

• un léger sac de couchage

The second version is possible only in special literary or stylistic contexts.

Both parce que and car can mean because, but they are used a bit differently.

In this sentence:

• parce que les nuits sont fraîches... = because the nights are cool...

Parce que is the most common and natural everyday way to give a reason.

Car is also correct, but it often sounds a bit more formal, written, or explanatory:

• Même en été, je prends un sac de couchage léger, car les nuits sont fraîches près de la mer.

So the original sentence uses the most conversational choice.

French often uses the definite article where English uses no article.

So:

• les nuits sont fraîches = the nights are cool but in natural English we usually say:
• nights are cool or
• the nights are cool

French prefers the article in general statements like this:

• Les chiens sont intelligents. = Dogs are intelligent.
• Les hivers sont longs ici. = Winters are long here.

So les nuits is completely normal.

Because fraîches agrees with les nuits.

• nuit is a feminine noun
• les nuits is plural
• so the adjective must also be feminine plural

Agreement forms:

• frais = masculine singular
• fraîche = feminine singular
• frais = masculine plural
• fraîches = feminine plural

Since nuits is feminine plural, French uses:

• les nuits sont fraîches

Not exactly. In this sentence, fraîches means:

• cool
• chilly
• fairly cold

When talking about weather, air, evenings, or nights, frais / fraîche often means cool rather than fresh.

So:

• les nuits sont fraîches = the nights are cool or
• the nights get chilly

That is why a sleeping bag is still useful even in summer.

Près de means near or close to.

It is a fixed expression:

• près de
  • noun

Examples:

• près de la mer = near the sea
• près du village = near the village
• près des montagnes = near the mountains

So in the sentence:

• près de la mer = near the sea

You need de after près. You cannot say près la mer.

Because près requires de, not à.

• près de la mer = near the sea
• loin de la mer = far from the sea

By contrast, à la mer usually means to the seaside or at the sea/seaside, depending on context:

• Je vais à la mer. = I’m going to the seaside.

So:

• près de la mer = near the sea
• à la mer = at/to the seaside

They mean different things.

Yes. The phrase Même en été is placed at the start as an introductory element, so a comma is very natural:

• Même en été, je prends...

It helps separate the emphasis phrase from the main clause.

The comma before parce que is also common here because the sentence has two clear parts:

• Même en été, je prends un sac de couchage léger,
• parce que les nuits sont fraîches près de la mer.

French punctuation often uses commas in places that feel similar to English, especially with longer clauses like this.

Yes, depending on the situation.

The present tense here suggests a habit or a general rule:

• Même en été, je prends un sac de couchage léger... = Even in summer, I take/bring a light sleeping bag...

If you are talking about one future trip, French could also say:

• Même en été, je prendrai un sac de couchage léger... = Even in summer, I’ll take a light sleeping bag...

So the present in the original sentence works well for something habitual or generally true.