Not only “speak English”, but if he has lived in Texas for 23 years, speak Texan!!!
Funny! My stepson came to America from Russia when he was 16 with no foreign language skills. In less than a year he was speaking perfectly good Texan (with no foreign accent)! His older brother had been taught the Queen's English in college and spoke that English when they arrived together. Today, they are humorous to listen to when they talk to each other. Neither like to speak Russian. In fact both are now serving in the U.S. Army have have asked their Russian born mother to neither talk nor write to them in Russian.