i see a big difference if a non english but spanish speaking foreigner moves to washington heights, one of the world's capital cities for the sons and daughters of Quisquea and to little Habana in Miami, or a non spanish just english speaking foreigner moving to the DR.
the big latin enclaves like dominican york/little habana etc do not require any english skills within those huge areas, everything within the 'hood is spanish, supermarkets show their signs in spanish, available newspapers in spanish, neighbourhood meetings in spanish, the Cop on the street speaks spanish etc etc, a only english speaking native/american would have trouble to be understood there.
and it has a simple reason, that reason is the large number of Latins living there at one place.
i would guess that in NY live more Latin people than Santo Domingo has citizens, so within such a large "Expat" community separated from the rest of the City's 'enclaves' like the Irish, the Italian, the Chinese and the americans etc etc there's no big need to speak any local language/english.
here on the Island it is different, here we do not have such large enclaves of just one foreign language/country at one spot, the numbers of persons from the same foreign country/language living together in the same neighbourhood is much smaller, here you find at all locations the need to speek spanish.
even in the tourist areas, take as an example Bavaro/Punta Cana here on the east, a huge tourist area with many foreigners/expats/foreign workers and retirees etc, but even here you do not come around without spanish. to speak only english would restrict you here to a few Bars where mostly some of the expats hang out, so your socializing would be restricted to those few locations and the few people who frequent those places permanently. at the moment you leave your house to interact in daily life you need to speak spanish or you will be very limited to simple hello/good bye/beer/sausage/rice etc conversations.
yes, many workers at the resorts speak english, but the very most of them do not socialize within the Bavaro/Punta Cana area, they are here for their job, when their shift is finished they drive home and that is for the very most of them not Bavaro/Punta Cana, for the very most the daily life/socializing etc is not taking place at the few ""expat"" locations/bars.
to live on the Island without beeing isolated from every days life requires absolutely to be able to communicate in spanish.
there's no need to be perfect on such, but if somebody who lives here can not have a simple conversation about the next election, a new car model, the jokes in a new movie at the cine etc, then this person is not really living here, just imprisioned in a foreign country.
and to really "live" with a non english speaking partner without good own spanish skills, come on, a partnership/marriage without the ability to communicate and discuss and like once in a while happening in every marriage even fight (verbally of course) with each others and on such express own points and understand the spouse's points very clear, i find it impossible that such really works without spanish, as long as somebody is not married with a perfect english speaking partner. and even if the dominican partner speaks a perfect english so the communication between the spouses is present, then the not spanish speaking partner would be out of the communications when visiting family, interacting with neighbours etc. and such person would be from one moment to an other stand alone in case the partnership ends.
i did not speak any word of spanish when i came down here, and i found it hard to learn during the first several months, but with time a little basic collection comes together and i became more selfconfident, don't worry that somebody would laugh about you for choosing a wrong word or pronouncing wrong, Dominicans don't do such, the opposite, they correct you in a friendly way and from this point on the learning goes faster and faster.
Dare to speak and of course listen, watch spanish channels on TV, old films you know from prior years in your own language, such things helped me to improve my spanish understanding and speaking.
today i can have any kind of conversation in spanish, directly or on the phone, doesn't matter about what theme, in case of a new movie it is the same to watch it in german or english or spanish.
yes, it took years to reach such point, and the learning and getting better on it never ends.
and of course the practice is the important point, you need to go out and be with people who speak only spanish, listen, chime in and dare to speak. the daily practice is important to progress.
Mike