El candado de combinación tiene un mecanismo.

Because candado is a masculine noun in Spanish, so it takes the masculine singular article el.

A good way to learn it is as one chunk:

el candado = the padlock / the lock

There is not always a logical reason a noun is masculine or feminine, so in many cases you simply memorize the noun together with its article.

Spanish usually does not stack nouns the way English does.

In English, combination lock uses combination like an adjective in front of lock.
In Spanish, that idea is often expressed with de:

candado de combinación = literally lock of combination

This is a very common pattern in Spanish:

• mesa de madera = wooden table / table made of wood
• cepillo de dientes = toothbrush
• sala de espera = waiting room

So de combinación is the natural way to say combination in this kind of phrase.

It is a prepositional phrase describing what kind of lock it is.

So:

• candado = lock / padlock
• de combinación = of combination / combination-type

Together, candado de combinación means combination lock.

In other words, de combinación functions like a classifier. It narrows down the meaning of candado.

The accent mark shows where the stress goes: com-bi-na-CIÓN.

Without the written accent, Spanish pronunciation rules would suggest a different stress pattern. The accent mark tells you that the final syllable is stressed.

This is very common with nouns ending in -ción:

• información
• situación
• combinación

These are usually stressed on the last syllable.

Tiene is the él/ella/usted form of the verb tener, which means to have.

The subject of the sentence is el candado de combinación, which is singular, so Spanish uses the singular form:

• tengo = I have
• tienes = you have
• tiene = he/she/it has

Here it means:

El candado de combinación tiene... = The combination lock has...

In English, the subject is it, but Spanish often just uses the noun itself instead of adding a separate subject pronoun.

Because tiene means has, while hay means there is / there are.

These are not interchangeable:

• El candado de combinación tiene un mecanismo. = The combination lock has a mechanism.
• Hay un mecanismo en el candado de combinación. = There is a mechanism in the combination lock.

Both can be correct, but they mean slightly different things and focus on different parts of the idea.

In Spanish, singular countable nouns usually need an article or some other determiner.

So Spanish normally says:

• un mecanismo = a mechanism
• el mecanismo = the mechanism

Leaving out the article would usually sound incomplete in a normal sentence.

Spanish does sometimes omit articles in special contexts, but not here. So tiene un mecanismo is the normal form.

Un is the indefinite article, like a or an in English.
El is the definite article, like the.

The sentence says un mecanismo because it introduces the mechanism as something unspecified:

it has a mechanism

If both speaker and listener already knew exactly which mechanism was being discussed, then el mecanismo could be possible in another context. But in this sentence, un is the natural choice.

Yes. Mecanismo is a masculine noun, so it uses un in the singular:

• un mecanismo
• el mecanismo

Many nouns ending in -o are masculine, and mecanismo follows that common pattern.

Normally, no. In a full sentence like this, Spanish usually needs the article:

El candado de combinación tiene un mecanismo.

Dropping el would sound unnatural unless you were using a very special style, such as a heading, label, dictionary entry, or very telegraphic note-taking.

So for normal speech and writing, keep el.

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

El candado de combinación tiene un mecanismo.

Spanish word order is somewhat flexible, but changes in order often change the emphasis. For example:

Un mecanismo tiene el candado de combinación sounds unusual and marked in most contexts.

For a learner, the safest choice is the standard order:

subject + verb + object

Yes, very often candado refers specifically to a padlock. In many contexts, that is the most natural translation.

So:

candado de combinación usually means combination padlock or combination lock, depending on context.

If you are talking about a small portable lock with a shackle, padlock is often the clearest English equivalent.

Yes, it is grammatical and understandable.

That said, depending on the context, a native speaker might choose a more specific or more natural-sounding sentence, for example:

• El candado de combinación tiene un mecanismo interno.
• El candado funciona con un mecanismo de combinación.

But the original sentence is still correct Spanish.

It would become:

Los candados de combinación tienen un mecanismo.

Changes:

• el → los
• candado → candados
• tiene → tienen

Notice that combinación stays singular here because it is part of the type name de combinación.

If you wanted the object to be plural too, you could say:

Los candados de combinación tienen mecanismos.

A simple pronunciation guide is:

el kan-DA-do de kom-bi-na-SYON TYE-ne oon me-ka-NEES-mo

A few helpful notes for Latin America:

• c before a sounds like k: candado
• ción sounds roughly like syon
• tiene begins with tye-
• un is pronounced roughly like oon

The main stresses are:

• canDAdo
• combinaCIÓN
• TIEne
• mecaNISmo