Cuando tenga tiempo, revisaré el último párrafo y haré un resumen aún más breve.

Because cuando often takes the present subjunctive when it refers to a future action that has not happened yet.

• Cuando tengo tiempo... = when I have time / whenever I have time
  This usually sounds like a habitual or general situation.
• Cuando tenga tiempo... = when I have time
  This refers to a specific future moment.

So in this sentence, the speaker is talking about something they will do later, not something they usually do.

The sentence has two parts:

1. Cuando tenga tiempo → a subordinate clause referring to a future condition/circumstance
2. revisaré... y haré... → the main clause, where the speaker states what they will do

In Spanish, after words like cuando, en cuanto, hasta que, and tan pronto como, you often use the subjunctive if the action is still in the future.

Then the main action is expressed normally, here with the future tense:

• revisaré
• haré

So the structure is:

• When I have time → uncertain/future circumstance → subjunctive
• I will revise... and I will make... → main future actions → future tense

Yes, in many contexts Spanish can use the present tense to talk about the future, especially in everyday speech.

For example:

• Cuando tenga tiempo, reviso el último párrafo y hago un resumen aún más breve.

This can sound more conversational, depending on context.

However, revisaré and haré make the future meaning very explicit and can sound a bit more deliberate or formal. Both are possible, but the version with the future tense is very natural.

Spanish usually omits subject pronouns when they are not needed, because the verb endings already show who the subject is.

• tenga here is understood as yo tenga
• revisaré clearly means I will revise
• haré clearly means I will make/do

Adding yo is possible, but it would usually be for emphasis, contrast, or clarity:

• Cuando yo tenga tiempo, revisaré...

In a neutral sentence, leaving out yo is the most natural option.

Because hacer is irregular in the future tense.

Instead of using the full infinitive stem, it changes:

• hacer → har-

Then the regular future endings are added:

• haré
• harás
• hará
• haremos
• haréis
• harán

This is one of several common irregular future stems in Spanish, like:

• tener → tendr-
• poner → pondr-
• salir → saldr-
• venir → vendr-

Because Cuando tenga tiempo is an introductory subordinate clause placed before the main clause.

Spanish often uses a comma after a fronted clause like this:

• Cuando tenga tiempo, revisaré el último párrafo.

If the order is reversed, the comma is usually not needed:

• Revisaré el último párrafo cuando tenga tiempo.

So the comma helps mark the break between the time clause and the main statement.

El último párrafo means the last paragraph.

The article el is used because the speaker is referring to a specific paragraph, not just any paragraph.

• un párrafo = a paragraph
• el párrafo = the paragraph
• el último párrafo = the last paragraph

Spanish uses definite articles very often when talking about something specific and identifiable.

In Spanish, adjectives can come after or before the noun, but the position can affect style, emphasis, or meaning.

Here, último before the noun is very natural:

• el último párrafo

This is the standard way to say the last paragraph.

With some adjectives, position matters more strongly. In this case, último before the noun clearly means last/final in sequence.

Más breve means briefer / shorter.

Aún más breve means even briefer / even shorter.

So aún adds the idea of an extra degree:

• breve = brief
• más breve = briefer
• aún más breve = even briefer

It suggests that the summary will not only be brief, but shorter than something already brief.

Here aún means something like even or still more, and in many contexts it can be replaced by todavía:

• aún más breve
• todavía más breve

Both are possible.

A useful guideline:

• aún often appears in more formal or written language
• todavía is very common in everyday speech

Also, when aún means still/yet, it is often interchangeable with todavía. In this sentence, it has the sense of even more.

Both can relate to shortness, but they are not always used in exactly the same way.

• breve usually means brief, especially for texts, speeches, summaries, explanations, etc.
• corto means short, often in a more general or physical sense, though it can also be used for texts.

So for a summary, un resumen breve sounds very natural and slightly more polished than un resumen corto.

Yes. In Spanish, once the subject is understood, it does not need to be repeated.

So:

• revisaré
• haré

both clearly refer to the same subject: I.

This is very common in Spanish, especially when several verbs are connected by y.

No. Cuando tendré tiempo is not correct here.

After cuando referring to a future event, Spanish normally uses the present subjunctive, not the future tense:

• Cuando tenga tiempo... ✅
• Cuando tendré tiempo... ❌

This is a very common difference from English, where English uses the present form in when I have time, while Spanish uses the subjunctive.

Yes, accent marks matter a lot in Spanish.

A few points here:

• revisaré and haré need accents because they are first-person singular future forms
• último and párrafo need accents because of stress rules
• aún often takes an accent when it means still or even

Without the accents, the words may be misspelled or could suggest a different pronunciation.

For example:

• hare is not the same standard written form as haré
• parrafo is incorrect; it should be párrafo

So learners should try to keep the accents, especially in writing.