De dertiende week begint.

In Dutch, singular countable nouns usually need an article or another determiner, just like in English.

So:

• de dertiende week = the thirteenth week
• een dertiende week would mean a thirteenth week, which is usually less natural unless the context really calls for it

Because the sentence refers to a specific week, Dutch uses de.

Dutch nouns take either de or het as their definite article.

• week is a de-word
• so you say de week

This is something you usually have to learn with each noun:

• de week = the week
• het jaar = the year

There is no special reason here tied to the meaning week; it is simply the article that belongs to this noun.

Dertiende is the ordinal form of dertien (thirteen).

So:

• dertien = thirteen
• dertiende = thirteenth

It works like:

• drie → derde = third
• tien → tiende = tenth
• dertien → dertiende = thirteenth

In the sentence, de dertiende week means the thirteenth week.

Dutch ordinal numbers are usually formed by adding -de or -ste.

For this number, the correct ordinal is:

• dertien → dertiende

Many common ordinals are irregular or need to be learned as fixed forms, so it is best to memorize them. A few examples:

• één → eerste
• twee → tweede
• drie → derde
• vier → vierde
• acht → achtste
• dertien → dertiende

So dertiende is just the normal ordinal form you must use for thirteenth.

Yes. In this sentence, dertiende is being used like an adjective before the noun week.

Dutch adjectives and ordinal numbers often take an -e ending when they come before a noun, especially after de.

So:

• de dertiende week
• de eerste dag
• de laatste maand

Compare this with some cases where the form may look different when not placed before a noun, but in a phrase like this, dertiende is exactly what you expect.

Yes. Begint is the present tense form of the verb beginnen (to begin).

Conjugation in the present tense:

• ik begin = I begin
• jij begint = you begin
• hij/zij/het begint = he/she/it begins
• de week begint = the week begins

Here, the subject is de dertiende week, which is singular, so Dutch uses begint.

Because Dutch main clauses normally follow the V2 rule: the finite verb comes in the second position.

Here the sentence is:

• De dertiende week = first position
• begint = second position

So the structure is:

Subject + finite verb

This is very common in simple Dutch statements.

For example:

• De les begint. = The lesson begins.
• Het jaar eindigt. = The year ends.

Yes, but it means something different.

• De dertiende week begint. = The thirteenth week begins / is beginning.
• De dertiende week is begonnen. = The thirteenth week has begun.

So:

• begint = present tense
• is begonnen = perfect tense

Both are correct Dutch, but they describe different time perspectives.

Usually, yes. In a sentence like this, it works very similarly.

• De week begint. = The week begins.
• De film begint om acht uur. = The film begins at eight o’clock.

Dutch also often uses beginnen met for to begin with / to start with something:

• Ik begin met lezen. = I begin by reading / I start reading.

So the basic meaning is very close to English.

A rough pronunciation guide is:

• De ≈ duh
• dertiende ≈ DAIR-teen-duh or DEHR-teen-duh
• week ≈ vake
• begint ≈ buh-GINT

A few useful pronunciation notes:

• w in Dutch sounds more like English v
• ee in week is a long vowel
• g in begint is the Dutch guttural g/ch sound, not the English g in go

A rough whole-sentence approximation:

duh DEHR-teen-duh vake buh-GINT

Because the sentence is about one specific week: the thirteenth week.

So Dutch uses the singular noun:

• de week = the week

If it were plural, you would get something like:

• de dertiende weken

But that would mean the thirteenth weeks, which usually does not make sense unless you are comparing multiple series or years.

Yes, depending on context, that is a natural English rendering.

Dutch de dertiende week literally means the thirteenth week, but in some contexts, especially schedules, school terms, pregnancy timelines, or calendars, English might phrase it as:

• Week thirteen begins
• The thirteenth week begins

Both are reasonable translations depending on style and context.

No, not in the middle of a sentence.

Dutch capitalization rules are simpler than English in some cases:

• ordinary nouns are not capitalized
• adjectives and ordinals are not capitalized either

So the normal form is:

• De dertiende week begint.

Only the first word is capitalized here because it begins the sentence.