Learn Hardcore Portuguese (Portugal): O ciúme às vezes deixa o namorado de mau humor. - Jealousy sometimes puts the boyfriend in a bad mood.

ciúme (singular) – the feeling of jealousy, seen as a general concept.
- O ciúme é um sentimento difícil.
ciúmes (plural) – often used in the expression “ter ciúmes” (“to be jealous / to feel jealousy”).
- Ele tem muitos ciúmes. = He is very jealous.

In your sentence, “O ciúme” (singular) is the subject, talking about jealousy as a feeling in general.

How do you pronounce “ciúme” and where is the stress?

ciúme has three syllables: ci-Ú-me.

The stress is on “ú” (because of the accent): ciÚme.
Rough pronunciation (European Portuguese): see-OO-muh
- ci = like see
- ú = like the “oo” in food but shorter
- final -e = a very short /ɨ/ or /ə/-type sound, like a weak “uh”.

The written accent (ú) only marks stress and vowel quality; it doesn’t change the number of syllables.

What’s the difference between “às vezes” and “as vezes”?

às vezes (with a grave accent) is an idiomatic adverbial phrase meaning “sometimes”.
- It is a + as vezes (preposition a
  - article as) → written with crase (à).
- O ciúme, às vezes, deixa o namorado de mau humor. = Jealousy sometimes puts the boyfriend in a bad mood.
as vezes (without accent) means “the times” (literal noun phrase):
- Todas as vezes que ele chega atrasado, ela fica chateada.
- = Every time / all the times he arrives late, she gets upset.

In your sentence, you must use “às vezes” = sometimes.

I thought “deixar” means “to leave”. Why does it here mean “to make/put”?

Deixar has several meanings; two important ones are:

to leave (literally):
- Deixei o livro na mesa. = I left the book on the table.
to make / to cause someone to be in a state (causative meaning):
- Essa notícia deixou-me muito feliz. = That news made me very happy.
- O filme deixou-os tristes. = The movie left/made them sad.

Your sentence uses meaning (2):

O ciúme (subject)
deixa (makes/puts/causes)
o namorado (the affected person)
de mau humor (in a bad mood / with bad temper)

So: Jealousy sometimes makes/puts the boyfriend in a bad mood.

Why do we say “de mau humor” and not “em mau humor”?

In Portuguese, the usual fixed expression for “in a good/bad mood” is:

estar de bom humor – to be in a good mood
estar de mau humor – to be in a bad mood

So with humor, the natural preposition is de, not em.

Examples:

Ele está de mau humor hoje. = He is in a bad mood today.
Ela ficou de bom humor depois do café. = She got into a good mood after the coffee.

Your sentence follows this pattern:

deixa o namorado de mau humor
= makes the boyfriend be in a bad mood

What’s the difference between “mau” and “mal”?

They’re easy to confuse but have different roles:

mau – adjective = “bad” (opposite of bom)
- Goes with nouns.
- um mau humor = a bad mood
- um mau dia = a bad day
mal – usually an adverb = “badly / poorly” (opposite of bem), and also a noun in some contexts.
- Ele canta mal. = He sings badly.
- Senti-me mal. = I felt bad / unwell.

So in “de mau humor”, you need mau (adjective) because it qualifies humor (a noun).

Can “namorado” mean both “boyfriend” and “girlfriend”, or is it only male?

namorado – masculine: boyfriend
namorada – feminine: girlfriend

So literally, “o namorado” refers to a male partner.

If you want it to be gender-neutral in Portuguese, you’d typically rephrase:

…deixa a pessoa de mau humor. = makes the person be in a bad mood.
Or make it plural and mixed: os namorados, but that usually means couples or boyfriends in general, not necessarily gender-neutral for one person.

Could I say “O ciúme às vezes deixa os namorados de mau humor”? What changes?

Yes, grammatically it’s fine:

O ciúme às vezes deixa os namorados de mau humor.

This changes the meaning from one specific boyfriend to boyfriends in general (or couples, depending on context):

Original: Jealousy sometimes makes the boyfriend (a specific one already known in context) be in a bad mood.
New: Jealousy sometimes makes boyfriends (people in relationships) be in a bad mood.

The structure and grammar stay the same; only the number and scope of namorado(s) change.

Can I move “às vezes” to another place in the sentence, like in English?

Yes, às vezes is flexible in position, although some options sound more natural than others. All of these are possible:

O ciúme às vezes deixa o namorado de mau humor.
Às vezes, o ciúme deixa o namorado de mau humor.
O ciúme deixa às vezes o namorado de mau humor. (possible, but less usual / a bit heavier)

Options 1 and 2 are the most natural in European Portuguese. Position 3 is grammatically correct but not the most idiomatic in everyday speech.

Is the verb tense here describing a habit, like English simple present?

Yes. “Deixa” is present indicative (3rd person singular of deixar):

O ciúme às vezes deixa o namorado de mau humor.
= Jealousy sometimes makes the boyfriend be in a bad mood.

This is the standard way to express general truths, repeated actions, or habits, exactly like the English simple present:

Ele chega tarde todos os dias. = He arrives late every day.
O ciúme às vezes deixa o namorado de mau humor. = Jealousy sometimes puts the boyfriend in a bad mood.

Could I replace “deixar” with “fazer” or “pôr” here?

You can, but the nuance changes slightly:

O ciúme às vezes deixa o namorado de mau humor.
– neutral, very natural, “makes / leaves him in a bad mood”.
O ciúme às vezes faz o namorado ficar de mau humor.
– more explicitly causal: “makes the boyfriend get into a bad mood.”
O ciúme às vezes põe o namorado de mau humor.
– also possible, more colloquial / vivid: literally “puts the boyfriend in a bad mood”.

All are understandable; “deixar … de mau humor” is probably the most straightforward and idiomatic in standard European Portuguese here.

Why isn’t there any article before “mau humor”? Why not “de um mau humor”?

Both are possible, but they’re not quite the same:

de mau humor (no article)
- Fixed expression = “in a bad mood”, a general emotional state.
- This is the normal, idiomatic way to talk about mood:
  - Ele está de mau humor. = He’s in a bad mood.
de um mau humor (with um)
- This sounds like “with such a bad temper / with a really bad mood”.
- It’s more specific/intensifying, often followed by a complement:
  - Ele chegou de um mau humor terrível. = He arrived in a terrible mood.

In your sentence, we want the general idea “in a bad mood”, so “de mau humor” (without article) is the natural choice.