El ingenio ayuda a resolver el acertijo.

Here, ingenio means ingenuity, cleverness, or wit—the ability to think of a smart solution.

It is not exactly the same as inteligencia.

• inteligencia = intelligence in a broader sense
• ingenio = clever, inventive mental quickness, especially for solving something tricky

So in this sentence, ingenio suggests the kind of clever thinking that helps someone crack a riddle.

In Spanish, abstract nouns often use the definite article when talking about them in a general sense.

So:

• El ingenio ayuda... = Ingenuity helps...

This is very natural in Spanish. English often drops the article with abstract nouns, but Spanish frequently keeps it.

Other examples:

• La paciencia es importante. = Patience is important.
• La inteligencia ayuda mucho. = Intelligence helps a lot.

After ayudar, Spanish commonly uses a + infinitive to mean to help do something.

So:

• ayuda a resolver = helps to solve / helps solve

That a links the verb ayuda with the action resolver.

More examples:

• Me ayuda a estudiar. = He/She helps me study.
• Esto ayuda a entender el problema. = This helps to understand the problem.

So the a here is not the personal a. It is just part of the pattern ayudar a + infinitive.

Because after a in this structure, Spanish uses the infinitive.

So:

• ayuda a resolver = helps to solve

Not:

• ayuda a resuelve ❌
• ayuda a resolviendo ❌

The infinitive is the basic verb form, like to solve in English.

Very common pattern:

• aprender a leer = to learn to read
• empezar a trabajar = to begin to work
• ayudar a resolver = to help solve

Acertijo usually means riddle or brain teaser—something that requires clever thinking to figure out.

It is related to puzzles, but it is not always exactly the same as:

• acertijo = riddle / brain teaser
• adivinanza = riddle, often more traditional or playful
• rompecabezas = puzzle, especially a puzzle or jigsaw-type problem

So resolver el acertijo is a very natural way to say solve the riddle.

Because acertijo is a masculine singular noun, and here it refers to a specific riddle, or at least the riddle being discussed.

So:

• el acertijo = the riddle

Spanish normally uses articles more often than English, and in this sentence the noun needs one.

Yes, ingenio is masculine, and the ending -o is a strong clue.

So:

• el ingenio
• not la ingenio ❌

That said, endings are helpful but not perfect rules in Spanish. Still, in this case, -o matches the masculine article el.

Because the subject is el ingenio, which is singular.

Structure:

• El ingenio = singular subject
• ayuda = third-person singular verb form

So the verb agrees with the subject.

Compare:

• El ingenio ayuda. = Ingenuity helps.
• Las buenas ideas ayudan. = Good ideas help.

Here it is a verb: (él/ella/ello) ayuda = helps

It can also be a noun in other contexts:

• La ayuda = help / aid

But in this sentence, it is clearly a verb because it follows the subject:

• El ingenio ayuda... = Ingenuity helps...

Both are fine in English.

Spanish:

• ayuda a resolver

English:

• helps solve the riddle
• helps to solve the riddle

Both are natural translations. English often drops to, but Spanish keeps the a in this structure.

Yes, but the original order is the most neutral and natural:

• El ingenio ayuda a resolver el acertijo.

Spanish can sometimes move things around for emphasis, but that would sound less neutral or more literary.

For a learner, the original word order is the best model:

• subject + verb + infinitive phrase + object

Yes, it is completely natural and standard in Latin American Spanish.

The vocabulary and grammar are widely understood across the Spanish-speaking world:

• ingenio
• ayuda a + infinitive
• resolver el acertijo

Nothing in the sentence sounds especially Spain-specific or region-specific.

It would still be grammatical, but the nuance changes.

• La inteligencia ayuda a resolver el acertijo.
  = Intelligence helps solve the riddle.

• El ingenio ayuda a resolver el acertijo.
  = Ingenuity / cleverness helps solve the riddle.

Inteligencia sounds broader and more general.
Ingenio emphasizes clever, inventive thinking—the kind that is especially useful for riddles.

So ingenio is actually a very good word choice here.

It is helpful, yes. Resolver is commonly used with things like:

• un problema = a problem
• un acertijo = a riddle
• una duda = a doubt/question
• un conflicto = a conflict

Examples:

• Resolver un problema
• Resolver un acertijo

This is very similar to English solve, so it is a useful verb to learn as a chunk with these nouns.