En octobre, même les adultes portent parfois un drôle de déguisement pour Halloween.

French normally uses en with months, seasons, and years:

• en octobre = in October
• en été = in summer
• en 2024 = in 2024

So en octobre is the standard way to say in October.

Also, unlike English, French month names are not capitalized, so it is octobre, not Octobre.

Here, même means even.

So:

• même les adultes = even adults

It adds emphasis, suggesting that not only children but adults too sometimes wear costumes.

Its position is important: putting même before les adultes makes it focus on that noun phrase.

French often uses the definite article to talk about people or things in a general sense.

So:

• les adultes = adults / adult people in general

English often drops the article in this kind of sentence, but French usually keeps it.

Compare:

• Les chats aiment dormir. = Cats like sleeping.
• Les adultes portent parfois... = Adults sometimes wear...

Portent is the 3rd person plural present tense of porter.

Here, porter means to wear:

• je porte = I wear
• tu portes = you wear
• il/elle porte = he/she wears
• ils/elles portent = they wear

Since the subject is les adultes (plural), French uses portent.

Be careful: porter can also mean to carry, depending on context. In this sentence, it clearly means to wear.

Parfois means sometimes.

In French, short adverbs like this often come after the conjugated verb:

• Ils mangent souvent ici. = They often eat here.
• Les adultes portent parfois... = Adults sometimes wear...

That is the most natural position here.

You may sometimes see adverbs in other positions for emphasis or style, but portent parfois is the normal, neutral word order.

Drôle can mean either funny or strange/odd, depending on context.

In un drôle de déguisement, it often suggests:

• a funny-looking costume
• a strange costume
• an odd costume

For Halloween, all of those ideas can fit. The exact nuance depends on the situation.

This is a very common French pattern:

• un drôle de + noun

It means something like:

• a funny/strange kind of ...
• a rather odd ...

Examples:

• un drôle de bruit = a strange noise
• une drôle d’idée = a strange/funny idea
• un drôle de déguisement = a funny/strange costume

So the de is part of the expression. You should learn drôle de as a chunk.

Notice also:

• un drôle de déguisement
  but
• une drôle d’idée

The de becomes d’ before a vowel sound.

Because the sentence means that each adult sometimes wears a costume. French often uses the singular in this kind of distributive idea.

So:

• les adultes portent parfois un drôle de déguisement
  means adults sometimes wear a funny/strange costume

It does not mean they all share one single costume. It means each person, individually, may wear one.

French could use the plural in other contexts, but the singular is very natural here.

Un déguisement means a costume or a disguise.

For Halloween, it is best translated as costume.

Related words:

• se déguiser = to dress up / to disguise oneself
• un déguisement d’Halloween = a Halloween costume

So in this sentence, déguisement is the thing people wear to look like something else.

Here, pour Halloween means for Halloween in the sense of:

• for the occasion of Halloween
• because it is Halloween
• as part of Halloween celebrations

It does not mean intended as a gift for Halloween. It means the costume is worn in connection with that holiday.

The comma separates the introductory time phrase from the rest of the sentence:

• En octobre, ...

This is very natural in writing, especially when the sentence begins with a phrase like in October, at school, on Sundays, etc.

It helps readability, but punctuation can vary depending on style. The meaning does not change.

Yes. That would still be a correct sentence:

• Même les adultes portent parfois un drôle de déguisement pour Halloween.

Adding En octobre simply sets the time frame clearly at the start: In October, ...

French often puts time expressions at the beginning of the sentence to give context first.

No. In verbs like this, the -ent ending of ils/elles forms is usually not pronounced.

So portent is pronounced like porte.

That means:

• il porte
• ils portent

sound the same in speech.

You understand the difference from the subject:

• il porte = he wears
• ils portent = they wear

Yes, it is very natural:

• En octobre = time expression
• même les adultes = subject with emphasis
• portent = verb
• parfois = adverb
• un drôle de déguisement = object
• pour Halloween = purpose/occasion

A very literal breakdown is:

• In October, even adults wear sometimes a funny/strange costume for Halloween.

But in natural English, you would usually say:

• In October, even adults sometimes wear funny Halloween costumes.
• In October, even adults sometimes wear a strange costume for Halloween.

So the French word order is normal, even if it does not match English perfectly word for word.