Musimy się naradzić.

Musimy is the 1st person plural present-tense form of musieć (to have to / must / need to).

So:

• muszę = I must
• musisz = you must
• musi = he/she/it must
• musimy = we must / we need to
• musicie = you all must
• muszą = they must

In this sentence, musimy tells you the subject is we, so Polish does not need a separate my (we).

Because in Polish, the verb ending usually already shows who the subject is.

• musimy already means we must
• so my musimy się naradzić is possible, but usually unnecessary

You would add my only for emphasis, contrast, or clarity, for example:

• My musimy się naradzić, a wy możecie już decydować.
  We need to discuss it, while you can already decide.

Się is a very common Polish reflexive particle. In naradzić się, it is part of the verb expression itself.

Here it does not literally mean ourselves in the way an English learner might expect. Instead, it helps form the verb naradzić się, which means something like:

• to confer
• to consult together
• to discuss something together before deciding

So it is best to learn naradzić się as a whole unit, not as naradzić + się = advise ourselves.

Yes, in Polish grammar it is treated as a verb used with się.

But for a learner, the most useful approach is:

• learn it as the fixed expression naradzić się
• understand it as to confer / to have a discussion together

Many Polish verbs with się do not translate neatly into English as literal reflexives. This is one of them.

Because after musimy (we must / we need to), Polish normally uses an infinitive.

So the pattern is:

• musimy + infinitive

Examples:

• Musimy iść. = We must go.
• Musimy poczekać. = We must wait.
• Musimy się naradzić. = We need to confer.

This works much like English must + base verb.

This is about aspect, which is very important in Polish.

• naradzić się = perfective
• naradzać się = imperfective

In this sentence, naradzić się is used because the idea is usually to have one complete discussion / consultation, with some sense of reaching a conclusion.

So:

• Musimy się naradzić.
  = We need to have a discussion and settle things.

By contrast, naradzać się would suggest an ongoing, repeated, or habitual process, which is less natural here in most contexts.

The difference is aspect:

• Musimy się naradzić = we need to have a discussion and complete it
• Musimy się naradzać = we need to be discussing / discuss repeatedly / be in consultation

The first one is much more natural in ordinary situations where people mean:

• We need to talk it over
• We need to consult
• We need to discuss it before deciding

The imperfective version would only fit special contexts, for example if someone is talking about a longer process or repeated consultations.

Yes, się is somewhat mobile in Polish, but some positions sound more natural than others.

Most natural here:

• Musimy się naradzić.

Also possible:

• Musimy naradzić się.

But the first version is more standard and natural in neutral speech.

In general, się often appears early in the sentence, usually after the first stressed element or after the finite verb.

A rough pronunciation guide:

• Musimy ≈ moo-SHIH-mih
• się ≈ roughly shyeh, but with a nasal vowel quality
• naradzić ≈ nah-RAH-jich

A few helpful notes:

• Polish stress usually falls on the second-to-last syllable
• so:
  • mu-SI-my
  • na-RA-dzić
• się contains ę, which is a nasal vowel; in normal speech its exact sound can vary depending on what follows

A rough full approximation could be:

• moo-SHIH-mih shyeh nah-RAH-jich

Not perfect, but close enough for a learner.

It can mean either, depending on context.

• must if the tone is stronger
• need to if the tone is softer or more practical

So Musimy się naradzić could be understood as:

• We must confer
• We need to discuss it
• We need to consult with each other

In everyday English, need to is often the most natural translation.

A very common pattern is:

• naradzić się nad czymś = to discuss / deliberate over something

For example:

• Musimy się nad tym naradzić.
  We need to discuss that.
• Musimy się naradzić nad planem.
  We need to discuss the plan.

You can also express who you are consulting with:

• naradzić się z kimś = to consult with someone

For example:

• Muszę się naradzić z kolegą.
  I need to consult with my colleague.

Yes, Musimy się naradzić is a natural and idiomatic sentence.

It sounds like something people would say when they want:

• a short discussion
• a consultation
• a moment to talk things over before making a decision

Depending on context, similar English translations could be:

• We need to talk it over.
• We need to discuss it.
• We need to confer.

So this is a very good real-life sentence to learn.