According to the Center of Multicultural Science the answer is actually generational.Opposed to first generation Hispanics that prefer Spanish language television , second and third generation Hispanics tend to use both languages but prefer to watch and listen to English programming. This is largely due to the degree of acculturation and place of birth. Most of the 3rd generation Hispanics are US born or have lived here long enough to assimilate into American culture and as a result generally communicate and prefer English . Having said that, most of these Millennials still preserve their Hispanic identity and enjoy content that is culturally relevant to them . For this reason, they may have a preference for English but are fully bilingual and bicultural and easily gravitate between one language to another. Yet, to target them on the basis of language it is also simplistic and erroneous; culture matters, birthplace matters, amount of acculturation matters and generation matters( 1st generation vs 3rd generation Hispanics.)
Per Pew Research Center a great number of Latinos that get their news from television (67 %) only 24 % of them still watch their news in Spanish, while the remainder 43% follow in both English and Spanish. This trend tends to differ as to where they are getting the news from and which media platform they use. For example, as the graph below from the 2012 study demonstrates, if they get the news from television 24% of Latinos listen to Spanish only, when newspaper and print both English and Spanish and when they use the internet , Latinos only search news in English. What is interesting is the age demographic that backs the study mentioned earlier, the older demographic uses Spanish only and get their information mainly through television or radio. Second generation Latinos, the English only increases a bit but the figures are high in both languages, and finally with internet use figures jump to 61 % .
Figure Pew Research Center
Their study also matched the previous hypothesis that more and more of them tend to be more English dominant although still speak Spanish at home.
Although generation matters, there is a cultural factor to Hispanics where a multi generational family lives in the same household and although younger Latinos have the purchasing power, they are highly influenced by their older peers and in many occasions tend to be the ones making the buying decisions themselves . So when we tend to think that advertisers need to reach the younger population( the coveted 18-49) they should think again and place more attention to the 55+ age group. ( Source:Targeting Billenials? Target Elders too).