Here are a few ideas you can suggest to help strengthen their language skills:
Encourage the student to sign up to read children’s books to a Pre-School or Kindergarten class. Or, take them to the public library and check out children’s books. The word-picture associations, along with reading out loud, will help teach vocabulary and help them become familiar and comfortable with pronunciation.
Label items in the host family home, using post-it notes or printed signs, to reinforce the names of household objects in English.
Turn on subtitles when the host family and student are watching TV to help the student follow along with what is happening. The combination of hearing and seeing the words will help with the acquisition of English words and phrases.