Articles, gender and plural in Spanish

Au programme

• How do you say "a book"? (libro is masculine)
• How do you say "the house"? (casa is feminine)
• Which definite article goes with problema?
• What does unos libros mean?
• You are 21. Complete: Tengo ___ años.
• The article los is used before a masculine plural noun.
• The plural of el lápiz is los lápizs.
• Match each definite article to the noun it fits.