General rule of thumb for language preference is that a PD will only pull off that list if there is a significant need for officers who speak a particular language. In communities that have such a need there is normally already a significant # of residents on the list who are bi-lingual, therefore while language preference can sometimes be beneficial to some residents is it almost never any help to non-residents.
Do some homework on consent decree communities on the civil service list. If you are Hispanic (guessing by the PR flag, you are) you may have some luck getting past the residency requirement. Either way, I'll give you some advice; if you are looking to get on to a Mass municipal Civil Service department the golden rule in the Commonwealth is patience. It can take years to get hired depending on where you live, and how well you do on written standardized tests