Aquí= Here <> Allí = There ---------<> Ahí = It´s a middle point between here and there ---<>--- Acá= Here, but in a more imprecise or loose sense of location ("por acá"= somewhere around here) --?-- Allá= There, sometimes very far away, but in a more imprecise or loose sense of location -----------------?

acá=aquí, allá=allí=ahí Generally speaking this is how it works, now, more specifically you might think that the ones ending in "í" have a slightly more specific point of reference, so "acá and allá" would roughly be "here and there" whilst the other ones could be imagined as if you were POINTING AT something ~slightly/subjectively more specific within the "here and there". Functionally, "allá" and "acá" are more used because they allow the use of "pa´ llá/cá" (short informal form of "para allá/acá") very common in Chilean Spanish. eg. "-¿Dónde está Ana? -No sé, no ha venido para acá./ No sé, se fué para allá. Saludos!

Por favor pueden responder en español, inglés o finés, gracias