Il venditore ambulante vende un soprammobile.

Because venditore starts with a normal consonant sound, v.

In Italian:

• il is used before most masculine singular nouns: il libro, il tavolo, il venditore
• lo is used before special consonant groups, such as:
  • z: lo zaino
  • s + consonant: lo studente
  • ps: lo psicologo
  • gn: lo gnomo

So il venditore is the correct form.

Venditore means seller or vendor.

Ambulante means itinerant, roving, or street/traveling in this context.

So venditore ambulante is a common way to say:

• street vendor
• peddler
• itinerant seller

Literally, it is something like wandering seller or traveling vendor, but the natural English meaning is street vendor.

Because in Italian, many adjectives normally come after the noun.

So:

• venditore ambulante = street vendor / itinerant vendor

This is very normal Italian word order.
English often puts adjectives before the noun, but Italian often puts them after it.

Also, here ambulante is not just giving a casual description; it helps classify the type of vendor. That is another reason why post-noun position feels natural.

Vende is the third-person singular present tense of vendere (to sell).

The present tense of vendere goes like this:

• io vendo = I sell
• tu vendi = you sell
• lui/lei vende = he/she sells
• noi vendiamo = we sell
• voi vendete = you all sell
• loro vendono = they sell

So in this sentence, vende means sells.

Because Italian usually does not need subject pronouns when the verb ending already shows the person.

Here, though, the subject is not a pronoun at all; it is the full noun phrase:

• Il venditore ambulante = the street vendor

So the sentence already has a clear subject.
You would only add lui for special emphasis or contrast.

Because soprammobile starts with a normal consonant sound, s followed by a vowel (so-), not s + consonant.

For masculine singular indefinite articles:

• un before most nouns: un libro, un venditore, un soprammobile
• uno before nouns beginning with:
  • z: uno zaino
  • s + consonant: uno studente
  • ps: uno psicologo
  • gn: uno gnomo

Since soprammobile begins with so-, the correct article is un.

Soprammobile is a noun for a small decorative household object, often something placed on a shelf, table, or cabinet.

Possible English equivalents are:

• ornament
• decorative object
• knickknack
• trinket
• mantelpiece ornament in some contexts

It is a common Italian word for a decorative item in the home.

It is one word: soprammobile.

Its plural is soprammobili.

So:

• un soprammobile = one decorative object
• due soprammobili = two decorative objects

This plural may look a little unusual at first, so it is worth memorizing.

Because ambulante is an adjective here, not a separate noun.

The article il belongs to the whole noun phrase:

• il venditore ambulante

That entire phrase means the street vendor.

So the structure is:

• il = the
• venditore = vendor
• ambulante = itinerant/street

You do not repeat the article before the adjective.

Yes. This is a very normal Italian sentence pattern:

• Subject + Verb + Object
• Il venditore ambulante vende un soprammobile.

That is the standard, neutral order.

Italian can sometimes change word order for emphasis, but this version is the most straightforward and natural for a learner.

A natural plural version would be:

I venditori ambulanti vendono soprammobili.

Here is what changed:

• il → i
• venditore → venditori
• ambulante → ambulanti
• vende → vendono
• un soprammobile → soprammobili

You could also say dei soprammobili if you want to keep the idea of some decorative objects.

A simple pronunciation guide is:

• il ven-di-TO-re am-bu-LAN-te VEN-de un so-pra-MO-bi-le

A few useful notes:

• stress in venditore is on -to-
• stress in ambulante is on -lan-
• stress in soprammobile is on -mo-

If you want a rough English-style approximation:

• eel ven-dee-TO-re am-boo-LAN-te VEN-de oon so-pra-MO-bee-le

That is only approximate, but it helps as a starting point.

Yes.

Ambulante is not limited to this one phrase. It can describe something or someone that is traveling, itinerant, or mobile rather than fixed in one place.

For example, it is often used with:

• commerciante ambulante = itinerant trader / street seller
• venditore ambulante = street vendor

So it carries the idea of moving around to sell rather than selling from a permanent shop.