For a large percentage of American Catholics (38%) per the article quoted below, Spanish is probably NOT a "foreign language." 
"Spanish in the U.S. also makes sense for demographic reasons. A sizable percentage of American Catholics—38%, according to CARA—are Hispanic. And the number is growing.  A few years ago, one study reported Hispanics accounted for 70% of the Catholic growth in the United States—and if trends continue, Hispanics could make up the majority of Catholics in this country by 2035."  
From http://www.patheos.com/blogs/deaconsbench/2015/09/im-sorry-pope-francis-this-is-america-and-we-speak-english/

Of course this is not to say that all people who identify as "Hispanic" speak Spanish. But if even half do, that's a lot of Spanish-speaking Catholics, and it doesn't even count readers in Mexico, Central, or South America.