Attraversiamo il ruscello.

Attraversiamo comes from the infinitive attraversare, which means to cross or to go across.

In this sentence, attraversiamo means we cross or we are crossing, depending on context.

The ending -iamo is the 1st person plural ending for many Italian verbs in the present tense, including -are verbs like attraversare.

So:

• attraverso = I cross
• attraversi = you cross
• attraversa = he/she/it crosses
• attraversiamo = we cross
• attraversate = you all cross
• attraversano = they cross

So attraversiamo tells you the subject is we.

Yes. Attraversiamo can mean either:

• we cross / we are crossing → present indicative
• let’s cross → 1st person plural imperative

The form is the same. The difference comes from context and often from punctuation or tone of voice.

For example:

• Attraversiamo il ruscello. = We cross the stream / We’re crossing the stream
• Attraversiamo il ruscello! = Let’s cross the stream!

Because your sentence ends with a period, it most naturally looks like a statement, but the imperative meaning is still possible in the right context.

Italian often drops subject pronouns when they are not needed, because the verb ending already shows who the subject is.

Since attraversiamo already means we cross, adding noi is usually unnecessary.

So:

• Attraversiamo il ruscello. = natural, common
• Noi attraversiamo il ruscello. = also correct, but more emphatic

You would use noi if you want contrast or emphasis, for example:

• Noi attraversiamo il ruscello, voi aspettate qui.
  We cross the stream, you wait here.

Italian uses definite articles very regularly. Il ruscello means the stream.

Here:

• il = the for a masculine singular noun beginning with most consonants
• ruscello = stream, brook

So il ruscello is simply the normal way to say the stream.

Ruscello means a small stream, brook, or sometimes creek.

It is not the same as river.

Compare:

• ruscello = stream / brook
• fiume = river
• torrente = torrent / fast-flowing stream

So il ruscello suggests something smaller than a river.

It works very much like English to cross when it takes a direct object.

So:

• Attraversiamo il ruscello. = We cross the stream.

There is no preposition needed before il ruscello.

This is an important point, because English learners may expect something like across. But in Italian, attraversare is already a transitive verb, so you directly say what is being crossed.

Other examples:

• Attraverso la strada. = I cross the street.
• Attraversano il ponte. = They cross the bridge.

No, this is a very normal Italian sentence pattern:

• Attraversiamo = verb
• il ruscello = direct object

Italian often allows flexible word order, but this sentence is perfectly standard and natural.

You could also change the word order in special contexts for emphasis, but Attraversiamo il ruscello is the straightforward default.

A simple pronunciation guide is:

• attraversiamo → at-tra-ver-SYAH-mo
• il → eel
• ruscello → roo-SCHEL-lo

A few useful pronunciation notes:

• The tt in attraversiamo is a real double consonant, so it is held a bit longer than a single t.
• In ruscello, sc before e sounds like sh.
• The stress is on:
  • attraverSIAmo
  • ruSCELlo

Yes. That would mean we are crossing the stream in a more explicitly ongoing sense.

Compare:

• Attraversiamo il ruscello.
  Can mean we cross, we are crossing, or sometimes let’s cross, depending on context.

• Stiamo attraversando il ruscello.
  More specifically means we are in the process of crossing the stream.

Italian often uses the simple present where English might prefer the present progressive.

The plural is ruscelli.

So:

• il ruscello = the stream
• i ruscelli = the streams

Because ruscello is a masculine singular noun ending in -o, it usually changes to -i in the plural.

Yes, it sounds completely natural.

It is a simple, correct sentence that a native speaker could use in narration, conversation, or instruction. The only thing that changes is the interpretation:

• as a statement: We cross / We’re crossing the stream
• as a suggestion or command: Let’s cross the stream

So grammatically and stylistically, it is perfectly normal Italian.