No quiero ese libro; prefiero este.

I don't want that book; I prefer this one.

Breakdown of No quiero ese libro; prefiero este.

• yo: I
• querer: to want
• el libro: the book
• ese: that

Questions & Answers about No quiero ese libro; prefiero este.

Why isn’t yo included before quiero and prefiero?

Because Spanish often leaves out subject pronouns when they are not needed. The verb endings already show who is doing the action:

• quiero = I want
• prefiero = I prefer

So No quiero ese libro; prefiero este sounds natural. You could add yo for emphasis or contrast:

• Yo no quiero ese libro; prefiero este.
  = I don’t want that book; I prefer this one.

Why does no come before the verb in No quiero?

In normal Spanish negation, no goes directly before the conjugated verb:

• No quiero = I don’t want
• No prefiero = I don’t prefer

That is the standard pattern. Spanish does not usually use a separate word like English do in negatives.

Why is there no a before ese libro?