Si este libro es complicado, buscaré otro.

If this book is complicated, I will look for another one.

Breakdown of Si este libro es complicado, buscaré otro.

• yo: I
• ser: to be
• el libro: the book
• este: this

Questions & Answers about Si este libro es complicado, buscaré otro.

Why is it si este libro es complicado and not si este libro sea complicado?

Because after si meaning if, Spanish normally uses the indicative, not the subjunctive, when talking about a real or possible condition.

So:

• Si este libro es complicado, buscaré otro. = If this book is complicated, I’ll look for another one.

Using sea here would sound wrong in standard Spanish for this kind of sentence.

A very common pattern is:

• Si + present indicative, future
• Si tengo tiempo, iré.
• Si hace frío, me quedaré en casa.

Why is buscaré in the future tense?

Because it expresses what the speaker will do if the condition is true.

• buscaré = I will look for / I will find / I will search for

The structure is:

• If X happens/is true, I will do Y

So:

• Si este libro es complicado, buscaré otro.

You could also hear other tenses depending on meaning:

• Si este libro es complicado, busco otro. = If this book is complicated, I look for another one / I’ll get another one.
• Si este libro es complicado, voy a buscar otro. = I’m going to look for another one.

But buscaré is a very natural choice for a future result.