Learn Spanish (Spain): Él no es tan ingenuo como para creer esa mentira. - He is not so naive as to believe that lie.

Él no es tan ingenuo como para creer esa mentira.

He is not so naive as to believe that lie.

Breakdown of Él no es tan ingenuo como para creer esa mentira.

ser

to be

él

he / him (after a preposition)

para

for / in order to (+ infinitive) / by (a deadline)

no / not

Questions & Answers about Él no es tan ingenuo como para creer esa mentira.

Why does this sentence use tan instead of tanto?

We use tan because it modifies the adjective ingenuo (naive). If we were modifying a noun, we would use a form of tanto (e.g., tantas mentiras). Tan translates to "so", while tanto means "so much" or "so many".

Why is como para followed by the infinitive creer here?

The phrase tan ... como para (so ... as to / enough to) is used to express a consequence or limitation. It requires an infinitive when the subject doesn't change. Because the person who is naive is the same person who would be believing the lie, we use the infinitive creer instead of a conjugated verb.

Could I say "tan ingenuo que..." instead of "tan ingenuo como para..."?

Yes, but the grammar changes. If you use que (that) to express the consequence, you have to conjugate the second verb. You would say tan ingenuo que creería (so naive that he would believe). The como para structure is a handy shortcut that lets you use the infinitive.

Why does the sentence use esa mentira instead of esta mentira?

Esa means "that" (pointing to something recently mentioned or closer to the listener), whereas esta means "this" (closer to the speaker). By using esa, the speaker distances themselves from the lie, implying it is a specific lie that was just brought up in conversation.