The translation su agrees in number with the noun which it modifies; their is translated by su, sus, depending on what follows: their father/mother su padre/madre; their books/magazines sus libros/revistas. For their used with parts of the body,
Find out how to write letters in Spanish, including advice on greetings, layout, endings...
The CAP (Curso de Adaptación Pedagógica) is a course taken in Spain by graduates with degrees in subjects other than education, who want to teach at secondary level. Students take a CAP in a particular subject, such as mathematics, literature, etc.