In the North of Mexico we always say "aquí" even when we say "ven aqui" and we also use "allá" instead of "allí" but in the south of Mexico and most of south America "acá" is used. What is correct depends on where you are. By the way I'm in Monterrey very close to the US

In the North of Mexico we always say "aquí" even when we say "ven aqui" and we also use "allá" instead of "allí" but in the south of Mexico and most of south America "acá" is used. What is correct depends on where you are. By the way I'm in Monterrey very close to the US.