Sie wollen heiraten.

Sie can mean either:

• you in the formal singular sense
• you in the formal plural sense
• they

Because Sie is capitalized here, it means the formal you, not they.

So Sie wollen heiraten. can mean:

• You want to get married. said politely to one person
• You want to get married. said politely to more than one person

German uses capitalization to help distinguish Sie = formal you from sie = she or they.

In German, the formal you is always written as Sie with a capital S.

Compare:

• sie = she
• sie = they
• Sie = you (formal)

So capitalization is very important here. Without it, the sentence could mean something completely different.

Because the subject is Sie.

The verb wollen means to want, and it changes depending on the subject:

• ich will = I want
• du willst = you want
• er/sie/es will = he/she/it wants
• wir wollen = we want
• ihr wollt = you want
• sie/Sie wollen = they / formal you want

Since the subject is Sie, the correct form is wollen.

This is a very common German structure.

• wollen is a modal verb
• heiraten is the main action verb

With modal verbs in German, the modal verb is conjugated, and the second verb usually stays in the infinitive form.

So:

• Sie wollen heiraten. = literally You want marry = natural English You want to get married

German does not use zu after a modal verb here. So you say:

• Sie wollen heiraten.

not

• Sie wollen zu heiraten.

Because German often puts the main infinitive at the end when there is a modal verb.

Pattern:

• subject + modal verb + ... + infinitive

Examples:

• Ich will gehen. = I want to go.
• Wir müssen arbeiten. = We must work.
• Sie wollen heiraten. = You want to get married.

This is a basic and very important German word-order rule.

It can be used in both ways, depending on context.

• jemanden heiraten = to marry someone
• heiraten on its own = to get married

In your sentence, there is no object, so it means:

• to get married

If you added a person, it could mean:

• Sie wollen Anna heiraten. = They / You want to marry Anna.

If you are speaking informally, you would not use Sie.

You would use:

• du willst heiraten. = you want to get married. (to one person, informal)
• ihr wollt heiraten. = you want to get married. (to more than one person, informal)

So the original sentence is specifically the formal version.

Not as written.

• Sie wollen heiraten. with a capital S means formal you want to get married
• sie wollen heiraten. with a lowercase s means they want to get married

In normal German writing, this distinction matters a lot.

wollen is stronger and more direct. It usually means a real intention or desire.

• Sie wollen heiraten. = You want to get married.

möchten is softer and more polite, often more like would like.

• Sie möchten heiraten. = You would like to get married.

In many situations, wollen sounds firmer and more definite than möchten.

A rough pronunciation guide is:

• Sie ≈ zee
• wollen ≈ VOL-len
• heiraten ≈ HY-rah-ten

A few details:

• w in German sounds like English v
• ie in Sie sounds like a long ee
• ei in heiraten sounds like English eye

So overall, something like:

• zee VOL-len HY-rah-ten

Yes. It is short, grammatical, and completely natural.

It sounds like a straightforward statement of intention:

• Sie wollen heiraten.

Depending on context, it could be said:

• to report someone’s plans
• to ask for confirmation
• in conversation about relationships or weddings

It is a very typical example of German modal verb word order.