Bueno Amigo/Buena Amiga
This is a great opportunity to explain that in Spanish nouns (a person, place, or thing, such as "friend") can be masculine or feminine. Usually, masculine nouns end in the letter -o (amigo) and feminine nouns end in the letter -a (amiga). The adjective (descriptive word) takes on the masculine or feminine nature of the noun (bueno amigo; buena amiga).
Most nouns are either masculine or feminine. But when we're talking about our friends who might be a boy or a girl, the word amigo/a can be either, depending on whom we're talking about. A good friend who is a girl is a buena amiga. A good friend who is a boy is a bueno amigo.
Phew! It seems like a lot of work to an adult, but to children who hear the Spanish language spoken early in their lives, it's easy. So encourage your Claxton student to get the hang of it now. Maybe by singing along with one of these videos: