Họ sẽ cưới ngày mai.

Here, họ means they.

A few useful notes:

• It is a third-person plural pronoun.
• In other positions, it can also mean them.
• In Vietnamese, speakers often use names or family-role words instead of pronouns, so họ can sound a bit neutral or context-based compared with everyday English they.

Also, họ can mean family name / surname in other contexts, but not in this sentence.

Sẽ is a future marker. It works a lot like English will.

So the pattern is:

• họ = subject
• sẽ = future
• cưới = verb

It does not change form for different subjects. You use sẽ the same way with tôi, bạn, anh ấy, họ, etc.

No. Vietnamese verbs do not conjugate like English verbs.

That means cưới stays cưới no matter who the subject is:

• tôi cưới
• bạn cưới
• họ cưới

Time is usually shown by:

• time words like ngày mai = tomorrow
• markers like sẽ for future
• context

So learners often need to stop looking for verb endings like -s, -ed, or different forms like am/is/are.

Cưới usually means to marry or to get married, depending on context.

It can be used:

• transitively: cưới ai = marry someone
• more generally: get married

In this sentence, because the meaning is already clear from context, cưới is being understood as get married.

Related words:

• đám cưới = wedding
• lễ cưới = wedding ceremony
• kết hôn = to marry / to get married (more formal)

Often, yes — cưới nhau is clearer if you mean they are marrying each other.

So:

• Họ sẽ cưới nhau ngày mai. = They will get married tomorrow.

Why add nhau?

• nhau shows a reciprocal action, like each other.

Without nhau, Họ sẽ cưới ngày mai can still be understood, especially if the meaning has already been given, but many learners will hear cưới nhau as the more explicit and natural version for get married to each other.

Because Vietnamese does not need that kind of helper verb here.

English often says:

• get married
• be married

Vietnamese can express the event directly with the main verb:

• cưới

So Vietnamese is being more compact here. You do not need a separate word for get in this sentence.

Yes, it can go at the beginning too.

Both are possible:

• Họ sẽ cưới ngày mai.
• Ngày mai, họ sẽ cưới.

Vietnamese time expressions are fairly flexible. Putting ngày mai at the end is normal, and putting it at the beginning can give it a little more emphasis, similar to Tomorrow, they will get married in English.

Yes, very often you can.

For example:

• Họ cưới ngày mai.

Because ngày mai already makes the time future, the sentence can still be understood perfectly well.

Adding sẽ makes the future meaning more explicit. It can sound a bit more like:

• a prediction
• a statement of intention
• a clearly marked future event

So both are possible, but sẽ is not always required.

Yes to both.

• ngày mai = the full, very common form for tomorrow
• mai = a shorter, very common spoken form

Examples:

• Họ sẽ cưới ngày mai.
• Họ sẽ cưới mai.

Both are understandable. Mai is more conversational.

Both can relate to marrying, but they are not exactly the same in tone.

• cưới = common, everyday, often tied to the wedding event itself
• kết hôn = more formal, more like to marry / to enter into marriage

For example:

• Họ sẽ cưới nhau ngày mai. = natural, everyday
• Họ sẽ kết hôn vào ngày mai. = grammatical, but more formal or official in tone

So in normal conversation, cưới is very common. In formal writing, legal language, or official announcements, kết hôn is more likely.

A very natural version would often be:

• Họ sẽ cưới nhau ngày mai.

Other natural possibilities include:

• Ngày mai họ cưới nhau.
• Họ cưới nhau vào ngày mai.
  (correct, though vào is often unnecessary here)

If you want to talk more about the wedding ceremony itself, you might also hear:

• Họ làm đám cưới ngày mai.

That is closer to They are having the wedding tomorrow.