A semana tem sete dias.

In Portuguese, it is very common to use the definite article (o, a, os, as) when talking about something in a general sense.

So:

• A semana tem sete dias. = The week has seven days.

In natural English, we usually say A week has seven days without the, but Portuguese often prefers the article here.

If you say just semana by itself, the sentence sounds incomplete.

Tem means has.

It comes from the verb ter, which usually means to have.

Here are a few present-tense forms:

• eu tenho = I have
• você / ele / ela tem = you / he / she has
• nós temos = we have
• vocês / eles / elas têm = you all / they have

So in A semana tem sete dias, tem matches the singular subject a semana.

Because a semana is singular.

• tem = singular (has)
• têm = plural (have)

Compare:

• A semana tem sete dias. = The week has seven days.
• As semanas têm sete dias. = The weeks have seven days.

The accent in têm helps show that it is the plural form.

Yes, you can.

• A semana tem sete dias.
• Uma semana tem sete dias.

Both are grammatical, but the nuance is a little different:

• A semana sounds more like a general fact about the week as a concept.
• Uma semana sounds more like any one week has seven days.

In many learning contexts, A semana tem sete dias is the more standard way to state the general fact.

Because it comes after the number sete.

In Portuguese, just like in English, nouns are usually plural after numbers greater than one:

• um dia = one day
• dois dias = two days
• sete dias = seven days

So sete dia would be incorrect.

Yes, in this sentence it is very similar.

Portuguese uses:

• Subject + Verb + Object/Complement

So:

• A semana = subject
• tem = verb
• sete dias = what it has

That makes the structure very close to English:

• The week has seven days.

Yes, semana is feminine.

You can tell because it uses the article a:

• a semana = the week

Many nouns ending in -a are feminine, and semana is one of them.

That matters for agreement:

• a semana longa = the long week
• uma semana boa = a good week

The adjectives also take feminine forms.

A simple approximate pronunciation is:

ah seh-MAH-nah tein SEH-chee JEE-ahs

A more IPA-style version would be roughly:

/a seˈmɐ̃nɐ tẽ ˈsɛtʃi ˈdʒias/

A few helpful notes:

• semana has stress on ma
• sete usually sounds like SEH-chee in much of Brazil
• dias often sounds like JEE-as
• tem has a nasal sound, not a fully pronounced English m

Yes. In Portuguese, ter is often used not only for possession, but also for characteristics or contents.

So A semana tem sete dias is completely natural.

It is similar to saying:

• O ano tem doze meses. = The year has twelve months.
• O carro tem quatro portas. = The car has four doors.

Portuguese uses ter in many cases where English also uses have.

Yes, a few alternatives are possible:

• Uma semana tem sete dias.
• São sete dias na semana.
• A semana é composta de sete dias. (more formal)

But A semana tem sete dias is simple, natural, and very common for learners to start with.

No. In Portuguese, these words are normally lowercase in the middle of a sentence:

• A semana tem sete dias.

You only capitalize the first word because it begins the sentence.

Also, names of days of the week in Portuguese are usually not capitalized either:

• segunda-feira
• terça-feira
• quarta-feira

That is different from English.