Con permiso, necesito pasar.

Literally, con permiso means with permission.

In real-life use, though, it works more like:

• excuse me
• if you’ll excuse me
• may I get by?

It is a very common polite expression when you want to move past someone, leave a space, or politely interrupt movement.

Because it comes after necesito.

In Spanish, after a conjugated verb like necesito (I need), the next verb often stays in the infinitive:

• Necesito pasar = I need to pass
• Necesito comer = I need to eat
• Necesito salir = I need to leave

So pasar is not conjugated because necesito is already the main conjugated verb.

Here, pasar means to pass, to get by, or to move through.

In this context, it usually means physical movement, such as:

• getting past a person in a hallway
• squeezing by someone in a crowded place
• moving through a doorway or aisle

Pasar has many meanings in Spanish, but in this sentence it is specifically about moving past someone or through a space.

Spanish often leaves out subject pronouns when they are already clear from the verb ending.

• necesito already means I need
• so yo necesito is usually unnecessary

Both are possible:

• Necesito pasar
• Yo necesito pasar

But the version without yo is more natural in most situations. You would usually add yo only for emphasis or contrast.

Yes, it is natural and polite.

It sounds like something you would say when:

• someone is blocking your way
• you need to get through a crowd
• you want to pass in front of someone politely

It is a little more explicit than just saying Con permiso, because necesito pasar explains why you are saying it.

In many everyday situations, just Con permiso is enough.

Yes. Very often, Con permiso by itself is enough.

For example, if you are:

• walking past someone
• leaving a table
• moving through a narrow space

you can simply say Con permiso.

Adding necesito pasar makes the intention clearer and can sound slightly more direct:

• Con permiso. = Excuse me
• Con permiso, necesito pasar. = Excuse me, I need to get by

They can overlap, but they are not exactly the same.

• Con permiso: used especially when you want to pass, move by, or politely make way
• Perdón: often used like sorry?, pardon?, or excuse me
• Disculpe: more like excuse me in a general polite sense, often a little more formal

If your main goal is physical movement through a space, con permiso is especially appropriate.

Examples:

• Con permiso, necesito pasar. = I need to get by.
• Perdón, no escuché. = Sorry, I didn’t hear.
• Disculpe, ¿dónde está el baño? = Excuse me, where is the bathroom?

Yes. Con permiso is a fixed expression.

Even though permiso is a noun, Spanish commonly uses certain prepositional phrases without an article in set expressions. So learners usually just memorize con permiso as one polite phrase.

You do not normally say con el permiso in this situation.

Yes, but the meaning changes a little.

• ¿Puedo pasar? = May I pass? / Can I get through?
• Necesito pasar. = I need to pass.

So:

• ¿Puedo pasar? sounds more like asking permission
• Necesito pasar sounds more like stating a need

Both are useful. In a very polite situation, you might hear:

• Con permiso, ¿puedo pasar?

If someone is simply blocking your way and you need to get through, Con permiso or Con permiso, necesito pasar works well.

It is fairly neutral and polite, so it works in both formal and informal situations.

Nothing in Con permiso, necesito pasar is strongly informal. You could say it to:

• a stranger
• a coworker
• an older person
• a friend

If you want to sound even more formal, you could use:

• Con permiso, ¿me permite pasar? = Excuse me, would you allow me to pass?

But for normal everyday use, your sentence is already polite.

A simple pronunciation guide is:

kohn pehr-MEE-soh, neh-seh-SEE-toh pah-SAHR

A few notes:

• r in permiso is a light tap
• rr does not appear here, so you do not need a strong rolled r
• the stress falls on:
  • perMIso
  • neceSIto
  • paSAR

Try to say it smoothly, with polite intonation: Con permiso, necesito pasar.

Yes, you can, but the tone is a little different.

• Necesito pasar = I need to pass
• Tengo que pasar = I have to pass

Both are understandable and natural. In many situations, they are very close. But:

• necesito can sound a bit more personal or situational
• tengo que can sound slightly more forceful or urgent

If you are politely trying to get by someone, necesito pasar often sounds a bit softer.

Yes. It would be understood throughout the Spanish-speaking world.

Even though your focus is Latin American Spanish, Con permiso, necesito pasar is standard and clear in other varieties of Spanish as well. It is not a region-specific sentence.