Learn Hardcore Spanish (Spain): Quiero participar en la manifestación del sábado con mis amigos. - I want to take part in Saturday's demonstration with my friends.

Participar de does exist, but it is used differently and is much less common in Spain. It often has the sense of to share in / to enjoy something:

participar de la alegría – to share in the joy

For street protests, Spaniards will practically always say participar en la manifestación.

Why is it Quiero participar and not Quiero participo?

After a conjugated verb like quiero, Spanish normally uses the infinitive (the base form) for the second verb:

Quiero participar. – I want to participate.
Quiero comer. – I want to eat.
Quiero salir. – I want to go out.

So the pattern is:

[conjugated verb] + [infinitive]

Using quiero participo would be like saying I want I participate in English, which is ungrammatical.

So:

Quiero participar ✅
Quiero participo ❌

Could I say Quisiera participar instead of Quiero participar? What is the difference?

Yes, you can say Quisiera participar. The difference is mainly tone and politeness.

Quiero participar
- Literally: I want to participate.
- Neutral, direct, very common in everyday speech.
- Sounds straightforward and confident.
Quisiera participar
- Literally: I would like to participate.
- More polite, more tentative or soft.
- Often used in formal situations or when you want to sound especially courteous.

In this exact context (talking about your plans with friends), Quiero participar is the most natural. Quisiera participar would sound a bit more formal or distant.

Why is it la manifestación and not una manifestación?

The definite article la shows that both the speaker and listener know which demonstration is being talked about:

la manifestación del sábado
→ the specific demonstration that is on Saturday.

If you say una manifestación, you are talking about an indefinite or unknown protest:

Quiero participar en una manifestación.
→ I want to join some demonstration (not a particular one the listener already knows about).

Here, because it’s the known demonstration taking place on Saturday (probably already mentioned in the conversation or in the news), Spanish uses la manifestación.

What exactly does del sábado mean here? Why del and not de el?

Del is simply the contraction of de + el:

de + el sábado → del sábado

You must contract de el to del whenever they come together:

el libro del profesor (not de el profesor)
la casa del vecino (not de el vecino)

In la manifestación del sábado:

de + el sábado literally: of the Saturday
Functionally: the demonstration on Saturday / Saturday’s demonstration.

It specifies which demonstration you mean: the one happening on Saturday, not some other day.

Could I say la manifestación el sábado instead of la manifestación del sábado?

Yes, but the nuance changes a bit:

la manifestación del sábado
- Focus: identifying which demonstration you mean.
- Like English Saturday’s demonstration or the demonstration on Saturday (as a defining label).
la manifestación el sábado
- Feels more like adding a time expression: the demonstration, on Saturday.
- Slightly more like: the demonstration, (which is) on Saturday.

In practice:

Quiero participar en la manifestación del sábado.
→ Emphasizes that it’s that particular Saturday demonstration (perhaps there are others on different days).
Quiero participar en la manifestación el sábado.
→ Grammatically fine, but sounds more like: I want to join the demonstration on Saturday (time detail, less like a label).

Both are correct; del sábado is very natural when the date identifies the event.

What’s the difference between Quiero participar en la manifestación and Quiero ir a la manifestación?

They are close, but not identical:

Quiero participar en la manifestación.
- Emphasis: actively taking part in the protest (marching, chanting, etc.).
- Similar to I want to take part in the demonstration.
Quiero ir a la manifestación.
- Emphasis: going there / attending; less explicit about how actively you’ll participate.
- Similar to I want to go to the demonstration.

In everyday speech, many people use ir a la manifestación and participar en la manifestación almost interchangeably, but participar en explicitly highlights involvement.

Can I change the word order? For example: Quiero participar con mis amigos en la manifestación del sábado?

Yes, Spanish allows some flexibility in word order, especially with phrases of time and manner/companions. These are all correct:

Quiero participar en la manifestación del sábado con mis amigos.
Quiero participar con mis amigos en la manifestación del sábado.
El sábado quiero participar en la manifestación con mis amigos.

Nuances:

Putting con mis amigos earlier can slightly emphasize with my friends.
Putting el sábado at the beginning (El sábado quiero…) highlights the time.

However, the original order is very natural and typical: participar en [event] con [people].

Why is it con mis amigos and not just con amigos?

Both are grammatically correct, but they don’t mean the same:

con mis amigos
- You are specifying which friends: my friends.
- Clear that you’ll be with your own group of friends.
con amigos
- Vague/indefinite: with (some) friends.
- Could imply with people who are friends, but without saying whose or which ones.

Usually, if you literally mean my friends, you should say con mis amigos.

Why is manifestación feminine? And is it the same as protesta?

Gender
- Manifestación ends in -ción, and nouns ending in -ción / -sión are almost always feminine in Spanish:
  - la manifestación
  - la canción (song)
  - la decisión (decision)
Meaning and usage (in Spain)
- manifestación: a public demonstration, usually organized, often in the streets, to show support or opposition to something; can be big and somewhat formal.
- protesta: more general term for a protest; can be small or big, not necessarily a massive march.

In many contexts the two can overlap, but in Spain, a typical large street protest is naturally called una manifestación.

In Spain, are there any other common words for this kind of event besides manifestación?

Yes, a few:

marcha – a march; often used for protest marches:
- una marcha contra el racismo
concentración – a gathering, often static rather than marching:
- una concentración frente al ayuntamiento
protesta – generic word for protest:
- una protesta de estudiantes

But in standard news and everyday speech in Spain, a big organized street protest is very often called una manifestación.

Could I use the future instead, like Participaré en la manifestación del sábado? How does that compare to Quiero participar…?

Yes, you can:

Quiero participar en la manifestación del sábado.
- Focus: your desire/intention now.
- You want to do it; it may or may not be certain yet.
Participaré en la manifestación del sábado.
- Simple future; focus: statement about the future.
- Sounds more like a plan or promise: you will participate.

In conversation, many Spaniards would also say:

Voy a participar en la manifestación del sábado.
→ Very common way to talk about near or planned future events, often more natural than the simple future participaré in everyday speech.

Is there any difference between Spanish from Spain and Latin American Spanish in this sentence?

The sentence:

Quiero participar en la manifestación del sábado con mis amigos.

is perfectly fine and fully understandable everywhere in the Spanish‑speaking world.

Small differences you might see elsewhere:

In some Latin American countries, people might more often say marcha instead of manifestación in everyday speech.
Participar en remains correct everywhere; the structure does not change.

If your goal is specifically Spanish from Spain, your original sentence sounds completely natural and idiomatic.