Learn Italian: Quello è il tuo libro e questa è la mia penna.

Yes, literally it translates to "the your book" and "the my pen." In Italian, possessive adjectives like tuo and mia almost always need a definite article (il, la, i, le) in front of them. It feels repetitive to English speakers, but it's a strict rule in Italian!

How do I know whether to use il tuo or la tua for "your"?

In Italian, the possessive adjective has to match the gender of the thing being owned, not the person who owns it. Since libro (book) is a masculine noun, you must use the masculine il tuo. If you were talking about "your pen," it would be la tua penna because penna is feminine.

Why does the word for "that" end in -o (quello) but the word for "this" ends in -a (questa)?

Words for "this" and "that" also have to match the gender of the noun they are pointing to. Quello is masculine because it points to the masculine libro. Questa is feminine because it points to the feminine penna.

The sentence has both è and e. What is the difference?