When should I use 'al'?

Question

I am trying to tell the difference between 'al' and 'a' to refer to a place.

I know that you usually use a to refer to a country. But when should you use al?

I am trying to teach someone the difference but I don't really know how to explain it. I use it all the time as a native speaker, but to explain it is a different story. I tried looking on the internet only to find differences between hay/ahi/ay etc... not really al.

Example:

Ana y yo vamos a ir al bar.

Why not

*Ana y yo vamos a ir a bar. (I know this is incorrect. As to why, that is the question)

EDIT

As per comments, then can I know when do I need the definite article "el"? Or if there is another explanation for al?

Answer 1

al is basically contraction of a el.

Ir a bar would be go to bar. Which is grammatically incorrect. Correct version is go to the bar or go to a bar. Thus correct Spanish version is ir al bar or ir a un bar.

In case of proper names (places, people), you don't usually prepend them with article (there are few exceptions). Thus the correct form is to say vamos a España.

Note however, that for example correct way is to say vamos a El Salvador, not vamos al Salvador.

Can I know when do I need the definite article "el"?

Always, unless you're using indefinite article or unless there is exception, which says that you shouldn't (eg. proper names).

Answer 2

Because if what's next to the "ir a" is a noun then that noun must be accompanied by the corresponding definite article and the noun. You can also use the contraction "al" instead of "a el" when the noun is masculine.

So this could be written as:

Ana y yo vamos a ir al bar.

Ana y yo vamos a ir a el bar.

× Ana y yo vamos a ir a bar (No definite article)

When the noun is feminine:

Ana y yo vamos a ir a la casa.

× Ana y yo vamos a ir al casa. (Incorrect usage casa is feminine noun)

There is an exception to this rule:

• When the noun is a proper name such as a name of a country, city, etc.

Vamos a ir a México este fin de semana.

If what's next to "ir a" acts like a single verb (perífrasis verbal) then you don't use a definite article neither a contraction.

Ana y yo vamos a ir a jugar.

Answer 3

As others have said,

al = a+el in all senses.

However, do not under any circumstances use it in a proper noun, like El Paso, where the artículo definido is a part of the name.

(x ) Voy Al Paso, Texas.

(✓) Voy a El Paso, Texas.

However, some countries require a artículo definido, when it is not part of the name.

Voy a la India.

Voy al Brasil.