No quiero perderme el documental sobre el mar.

Because in Spanish, perderse algo often means to miss something.

So:

• perder = to lose
• perderse
  • a thing/event = to miss it

In this sentence, No quiero perderme el documental means I don’t want to miss the documentary.

Without me, perder el documental would sound more like to lose the documentary, not to miss watching it.

The me refers to myself, but in this expression it is not translated word-for-word as myself in natural English.

In perderme el documental, the me is part of the structure perderse algo, which means to miss something.

So although me literally points to me, the natural meaning is simply:

• No quiero perderme el documental = I don’t want to miss the documentary

Because perder is an infinitive, and in Spanish object/reflexive pronouns can be attached directly to an infinitive.

That is why you get:

• No quiero perderme el documental

But you can also place the pronoun before the conjugated verb:

• No me quiero perder el documental

Both are correct and very common. The meaning is the same.

In most situations, there is no real difference in meaning. Both mean:

• I don’t want to miss the documentary

The difference is mainly one of pronoun placement:

• No quiero perderme...
• No me quiero perder...

Spanish often allows both options when there is a conjugated verb plus an infinitive. A learner should understand and be comfortable with both.

Because querer is a stem-changing verb.

In the present tense, the e in the stem changes to ie in most forms:

• yo quiero
• tú quieres
• él/ella quiere
• nosotros queremos
• vosotros queréis
• ellos quieren

So quiero is the correct yo form.

In Spanish, simple negation usually works by putting no directly before the conjugated verb.

Here the conjugated verb is quiero, so:

• No quiero... = I don’t want...

This is the normal Spanish word order for negation.

El documental means the documentary, so it refers to a specific documentary.

That suggests the speaker has a particular documentary in mind, perhaps one already mentioned or known from the context.

If you said un documental, it would mean a documentary, which sounds less specific:

• No quiero perderme un documental sobre el mar = I don’t want to miss a documentary about the sea

That could work, but it is a different meaning.

Sobre here means about or on the subject of.

So:

• un documental sobre el mar = a documentary about the sea

This is a very common use of sobre with topics:

• un libro sobre historia = a book about history
• una charla sobre arte = a talk about art

Sometimes del mar can work, but it is not exactly the same.

• sobre el mar = about the sea / focused on the sea as a topic
• del mar = of the sea / from the sea / related to the sea

For a documentary title or description, sobre el mar is the clearest way to say about the sea.

For example:

• un documental sobre el mar = a documentary whose subject is the sea
• animales del mar = animals of the sea / sea animals

Yes, mar is interesting because it can be masculine or feminine, depending on style, region, and context.

In general modern standard Spanish, el mar is the most common form, especially in everyday language.

So:

• el mar = the sea

You may also hear la mar, especially in poetic language, nautical language, or some regional varieties, but for most learners el mar is the safest and most standard choice.

Yes. Perderse has more than one meaning, and context tells you which one is meant.

Common meanings include:

• to get lost
  
  • Me perdí en la ciudad = I got lost in the city
• to miss
  
  • No quiero perderme el documental = I don’t want to miss the documentary

In this sentence, because the object is el documental, the meaning is clearly to miss, not to get lost.

Yes. Mar usually means sea, but in some contexts English might naturally use ocean depending on style or subject matter.

The most direct translation is:

• I don’t want to miss the documentary about the sea

But if the documentary is really about ocean life or the open ocean, English might sometimes prefer ocean. The Spanish sentence itself uses mar, so sea is the closest match.