Learn Hardcore Spanish (Spain): Cuando tenga tiempo, leeré otra novela de esta autora. - When I have time, I will read another novel by this author.

Tenga is in the present subjunctive. Spanish uses the subjunctive after cuando when you are talking about a future event that is not yet real or certain.

Cuando tenga tiempo, leeré…
= When I have time (in the future, not yet true), I will read…

If you used the indicative tengo, it would mean something habitual or generally true, not a specific future moment:

Cuando tengo tiempo, leo otra novela.
= When(ever) I have time, I (usually) read another novel.

So: future, not yet realized → subjunctive (tenga), not tengo.

In general, when do I use subjunctive vs indicative with cuando?

Very broadly:

Indicative (present/past) with cuando = something habitual, general, or completed:
- Cuando tengo tiempo, leo. – Whenever I have time, I read. (habit)
- Cuando llegaste, ya estaba aquí. – When you arrived, I was already here. (completed past)
Subjunctive with cuando = a future event that has not happened yet (or is uncertain):
- Cuando tenga tiempo, leeré. – When I have time, I’ll read. (future, not yet real)
- Te llamaré cuando llegue. – I’ll call you when I arrive.

So you choose:

habit / fact / completed → indicative
future / not yet real / uncertain → subjunctive

Why don’t we say Cuando tendré tiempo, leeré… with the future tense?

In Spanish, after time expressions like cuando, antes de que, después de que, etc., you normally do not use the future tense in the subordinate clause. You use the present subjunctive instead when referring to the future.

So:

✅ Cuando tenga tiempo, leeré otra novela.
❌ Cuando tendré tiempo, leeré otra novela.

Even though in English you say “When I will have time, I will read…” (normally simplified to “When I have time”), Spanish avoids future in that subordinate clause and uses subjunctive.

Could I say Cuando tenga tiempo, voy a leer otra novela… instead of leeré? Is there any difference?

Yes, you can say:

Cuando tenga tiempo, voy a leer otra novela de esta autora.

Both leeré (simple future) and voy a leer (near future) are fine in Spain.

Nuance (often quite small):

Leeré: somewhat more formal, neutral, or distant future.
Voy a leer: slightly more immediate or “planned” future, more colloquial.

In everyday spoken Spanish, voy a + infinitive is extremely common. Grammatically, both are correct.

Is the comma after tiempo necessary?

Yes, it is standard and recommended here.

In Spanish, when a dependent clause (like cuando tenga tiempo) comes before the main clause, you normally separate them with a comma:

Cuando tenga tiempo, leeré otra novela…

If the order is reversed, the comma is usually omitted:

Leeré otra novela de esta autora cuando tenga tiempo.

So the comma in the original sentence is correct and natural.

Why is it de esta autora and not por esta autora for “by this author”?

For books, songs, paintings, etc., Spanish usually uses de to indicate authorship:

una novela de García Márquez – a novel by García Márquez
una canción de Sabina – a song by Sabina

Por is used:

for the agent in a passive construction:
- Fue escrito por García Márquez. – It was written by García Márquez.
for cause, means, movement through, etc.:

So:

una novela de esta autora = a novel by this female author
Using por esta autora here sounds unnatural; it suggests the passive pattern (fue escrita por…), which is not what you have in this sentence.

Why is it esta autora and not este autora?

Because autora is feminine, and demonstratives agree in gender and number with the noun:

el autor → este autor (masculine singular)
la autora → esta autora (feminine singular)

So:

esta autora = this (female) author
este autor = this (male) author

In Spain, it’s common and natural to use the feminine form autora when referring to a woman.

Could I say Cuando tengo tiempo, leeré otra novela… with tengo instead of tenga?

You can, but it changes the meaning.

Cuando tenga tiempo, leeré…
Focus on a specific future moment when you finally have time (not yet true) → subjunctive.
Cuando tengo tiempo, leeré…
Sounds odd, because you mix a habitual present clause (cuando tengo tiempo) with a future main verb (leeré). A more natural habitual version would be:
- Cuando tengo tiempo, leo otra novela de esta autora.

So if you keep leeré (future), tenga (subjunctive) is the natural and correct choice.

Does tenga refer to the present or the future? It looks like a present tense.

Grammatically, tenga is present subjunctive, but here it refers to a future situation.

Spanish often uses the present subjunctive to talk about future events in subordinate clauses:

Cuando llegue, te llamo / te llamaré. – When I arrive (in the future)…
Cuando termine, te aviso. – When I finish (in the future)…

So the form is “present subjunctive,” but the meaning is future because of the context and the main verb leeré.

Why is it otra novela and not una otra novela?

In Spanish, you do not put an article before otro/otra:

✅ otra novela – another novel
❌ una otra novela

The word otro/otra itself already includes the idea of “one more / another,” so adding un/una is redundant and incorrect in standard Spanish.

Could I say yo leeré otra novela instead of just leeré otra novela?

Yes, you can say:

Cuando tenga tiempo, yo leeré otra novela de esta autora.

Including yo is grammatically correct, but in neutral Spanish it’s usually omitted because the ending -é already shows the subject is yo.

You include yo mainly:

for contrast or emphasis:
- Cuando tenga tiempo, yo leeré otra novela, y tú mirarás la tele.

Without emphasis, the most natural version is the original:
Cuando tenga tiempo, leeré otra novela de esta autora.

What’s the difference between Cuando tenga tiempo, leeré… and Cuando tengo tiempo, leo…?

Meaning:

Cuando tenga tiempo, leeré otra novela…
→ Refers to a specific future situation (not yet real).
“When I (finally) have time, I will read another novel…”
Cuando tengo tiempo, leo otra novela…
→ Describes a habit or routine now or generally.
“Whenever I have time, I (usually) read another novel…”

So:

tenga + future (leeré) → one or more future occasions, not yet realized.
tengo + present (leo) → habitual behavior.