Adverbs of location describe where an action takes place. These locations can be divided up into two general categories:
1. Nearby the speaker
2. At a distance form the speaker.
For those actions nearby the speaker, we use "acá" (here) and "aquí" (over here) interchangeably. While you will be understood no matter which form you choose, there are some things to note here. For starters, "acá" is generally used more in Latin America, and "aquí" is more commonly used in Spain. It should also be mentioned that "acá" is often used to refer to a larger area that is "here", while "aquí" is sometimes used to pinpoint location with more precision.
For those actions at a distance from the speaker, we also use "allá" (over there) and "ahí" (there) interchangeably. While both words serve in most situations, "allá" generally refers to things that are farther away; "ahí" refers to things at a closer distance. There is an alternative spelling for "ahí" as well: "allí". The meaning is the same, and you will find that various regions choose to spell the same word one way and not the other.
These adverbs of location are indeclinable, which means that their form never changes. This makes them easy to remember.
Near the Speaker:
acá, aquí (here, over here)
At a Distance from the Speaker:
allá, ahí (over there, there)
You may notice that the preposition "para" (for, in order to) is often used before these adverbs of location. When it is, the meaning of the preposition changes to "in the direction of", so to speak.
For example, we can say "¡Ven acá!" (Come here), or "¡Ven para acá!" (Come over here!).
La fiesta es acá.
(The party is here.)
Aquí están José y Miguel.
(Here are José and Miguel.)
Vamos para allá.
(We’re going over there.)
(They eat lunch there.)
Adverbs of location are important because they tell where the action of a verb takes place. Of course, there are many more of this kind of adverb, but with these, you will be able to make large distinctions.