Pase lo que pase, quiero terminar la reseña esta noche y entender mejor al personaje principal.

Because this expression uses the subjunctive, not the indicative.

Pase lo que pase is a fixed structure meaning no matter what happens or whatever happens. Spanish uses the subjunctive here because the event is indefinite or open-ended: you are not talking about a specific known event, but about any possible thing that might happen.

• pasa = indicative, used for facts or things presented as real
• pase = subjunctive, used here for uncertainty, possibility, or concession

So:

• Pase lo que pase = Whatever happens / No matter what happens

Using pasa lo que pasa would not sound right in this meaning.

Here lo que means something like what(ever) or that which.

In this pattern:

• pase lo que pase

the middle part lo que helps create the meaning whatever.

A very literal breakdown is:

• pase = may happen
• lo que = what / whatever
• pase = happens

So the whole expression works like:

• Whatever happens
• No matter what happens

This is an idiomatic Spanish structure, so it is best learned as a whole chunk: pase lo que pase.

Yes. It is a very common fixed expression in Spanish.

You can think of it as one unit meaning:

• whatever happens
• come what may
• no matter what happens

Even though you can analyse the grammar, learners usually benefit from memorising it as a complete phrase.

Similar fixed patterns exist in Spanish, such as:

• sea como sea = however it may be / one way or another
• cueste lo que cueste = whatever it costs
• vaya donde vaya = wherever he/she goes

Because Pase lo que pase is an introductory concessive phrase.

It sets the scene for the main clause:

• Pase lo que pase,
• quiero terminar la reseña esta noche...

In English, this is similar to writing:

• Whatever happens, I want to finish the review tonight...

The comma helps separate the introductory idea from the main statement.

Because both infinitives depend on the same verb quiero.

The structure is:

• quiero terminar... y entender...

This means:

• I want to finish... and understand...

Spanish does not need to repeat quiero before the second infinitive unless you want extra emphasis.

So these are both correct in meaning, but the first is more natural:

• Quiero terminar la reseña esta noche y entender mejor al personaje principal.
• Quiero terminar la reseña esta noche y quiero entender mejor al personaje principal.

The second version is more repetitive and would usually only be used for emphasis.

Because after querer (to want), Spanish normally uses an infinitive.

Pattern:

• querer + infinitive

Examples:

• Quiero comer. = I want to eat.
• Quiero dormir. = I want to sleep.
• Quiero terminar la reseña. = I want to finish the review.

So here:

• quiero terminar
• y entender

both follow that same rule.

La reseña refers to a specific review, not just any review.

So the speaker probably has a particular review in mind, for example:

• the review they are writing
• the review already mentioned in conversation
• the review assigned for homework or work

Compare:

• Quiero terminar la reseña = I want to finish the review
• Quiero terminar una reseña = I want to finish a review

Spanish often uses the definite article when the thing is already understood from context.

Here reseña most naturally means review.

For example, it could be:

• a book review
• a film review
• a review of a play or series

Depending on context, reseña can also mean a short write-up, summary, or overview, but in this sentence review is probably the best fit.

In Spain, reseña is a normal and common word in this sense.

Both are possible, but esta noche is shorter and very natural.

• esta noche = tonight
• hoy por la noche = tonight / today at night

In many contexts, esta noche is the most direct and idiomatic way to say tonight.

So:

• Quiero terminar la reseña esta noche = I want to finish the review tonight

Using hoy por la noche would also be understandable, but it is a bit more explicit and sometimes slightly heavier stylistically.

This is because of the personal a.

In Spanish, when the direct object is a specific person—or something treated like a person, such as a named character—you usually use a.

Here, el personaje principal is a character, and the speaker wants to understand that character better, so Spanish uses the personal a:

• entender al personaje principal

Also, al is just a contraction of:

• a + el = al

So:

• a el personaje principal → al personaje principal

Because Spanish often treats fictional characters grammatically like people when they are viewed as individual beings.

So even though the character is fictional, it is still a specific person-like entity. That is why the personal a sounds natural.

Compare:

• Entiendo al protagonista. = I understand the protagonist.
• Veo al personaje principal. = I see the main character.

But if the object is not person-like, there is no personal a:

• Entiendo el problema. = I understand the problem.

Because mejor modifies entender, not personaje principal.

So:

• entender mejor al personaje principal = to understand the main character better

The adverb mejor is placed near the verb it modifies.

This word order is the most natural one. You might also hear:

• entender al personaje principal mejor

but that usually sounds a little less neutral or may place slightly more focus on mejor.

So the sentence’s version is the standard, natural order.

Yes, often they could.

• entender = to understand
• comprender = to understand

In many situations they are very close in meaning. However, entender is extremely common in everyday Spanish and sounds very natural here.

So:

• entender mejor al personaje principal
• comprender mejor al personaje principal

Both work, though entender is probably the more straightforward everyday choice.

Because Spanish often leaves out subject pronouns when they are not needed.

The verb form quiero already tells you the subject is I:

• quiero = I want

So yo is optional:

• Quiero terminar la reseña... = normal
• Yo quiero terminar la reseña... = more emphatic

Spanish usually omits pronouns unless the speaker wants contrast, emphasis, or clarity.

Not directly. It sets up the meaning of concession, but the main clause still works normally:

• Pase lo que pase,
• quiero terminar la reseña esta noche y entender mejor al personaje principal.

So the main clause keeps:

• quiero in the present indicative
• infinitives terminar and entender

In other words, pase lo que pase adds the idea regardless of circumstances, but it does not force the rest of the sentence into the subjunctive.