Ce sont les voyageurs.

French often uses c’est / ce sont to identify or present someone or something.

So Ce sont les voyageurs is the normal way to say These/Those are the travelers or It is the travelers in an identifying sense.

• ce sont = these/those are / it is ... with a plural noun
• ils sont usually means they are and is more often followed by an adjective or a description:
  • Ils sont fatigués = They are tired
  • Ce sont les voyageurs = They are the travelers / Those are the travelers

So ce sont is used here because the sentence is naming or identifying a group.

In this sentence, ce is a demonstrative word meaning something like this, that, these, or those, depending on context.

In ce sont, it does not translate word-for-word neatly into English. It is part of a fixed pattern used for identification:

• C’est Marie.
• Ce sont mes amis.
• Ce sont les voyageurs.

So it is best to learn c’est and ce sont as common expressions rather than trying to translate ce by itself every time.

Because les voyageurs is plural.

The verb être must agree with the noun that follows in this structure:

• C’est le voyageur. = singular
• Ce sont les voyageurs. = plural

So:

• est = singular form of être
• sont = plural form of être

Yes, but in casual spoken French, many native speakers often say C’est les voyageurs instead of the more grammatically traditional Ce sont les voyageurs.

So you may hear both:

• Ce sont les voyageurs — more careful or standard
• C’est les voyageurs — very common in everyday speech

If you are learning standard French, it is best to produce Ce sont les voyageurs in writing and formal speaking.

Les is the plural definite article, meaning the.

So:

• le voyageur = the traveler (masculine singular)
• les voyageurs = the travelers (plural)

French usually requires an article before a noun, much more often than English does. So you normally say les voyageurs, not just voyageurs by itself in this sentence.

The singular version is:

C’est le voyageur.

Notice the changes:

• ce sont → c’est
• les voyageurs → le voyageur

So French changes both the verb form and the noun phrase to match singular vs. plural.

A careful pronunciation is approximately:

suh son lay vwa-ya-ZHUR

A few notes:

• Ce in ce sont sounds like suh
• sont sounds like son with a nasal vowel; the t is not pronounced
• les sounds like lay
• voyageurs is roughly vwa-ya-ZHUR

The last part -geurs has the soft j sound, like the s in measure.

Yes. There is normally a liaison between sont and les:

• Ce sont les voyageurs
• pronounced roughly: suh son-lay vwa-ya-ZHUR

That means the normally silent final t of sont is heard as a z sound before les.

So it sounds like son-lay, not two completely separate words.

The -s marks the plural in writing.

In French, many plural endings are not pronounced when the next word does not trigger a liaison. So:

• voyageur = singular
• voyageurs = plural

Even though the final -s is usually silent, it is still important in spelling and grammar.

Yes, but it means something slightly different.

• Ce sont les voyageurs = These/Those are the travelers or They are the travelers
  This refers to a specific group already known or identified.
• Ce sont des voyageurs = They are travelers / These are some travelers
  This is more general and less specific.

So les points to a definite group, while des is indefinite.

Voyageurs is the masculine plural form.

Forms:

• voyageur = masculine singular
• voyageurs = masculine plural
• voyageuse = feminine singular
• voyageuses = feminine plural

So if the group were entirely female, you could say:

Ce sont les voyageuses.

If the group is mixed or gender is unspecified, French normally uses the masculine plural:

Ce sont les voyageurs.

Yes, ce can absolutely be used before être to identify people.

For example:

• C’est Paul.
• Ce sont mes parents.
• Ce sont les voyageurs.

So even though learners often first meet ce as this/that, in the pattern c’est / ce sont, it is very commonly used with people as well as things.