Questions & Answers about El padre de la amiga es joven.
Why is it El padre de la amiga instead of using an apostrophe 's' like in English?
Spanish doesn't use an apostrophe 's' for possession. Instead, you always use the formula 'the [thing owned] + de + the [owner]'. So, 'the friend's father' becomes El padre de la amiga (literally: the father of the female friend).
How do we know this is a female friend?
The word amiga ends in an 'a' and uses the feminine word for 'the', which is la. If it were a male friend, the sentence would say El padre del amigo es joven, combining de and el into the single word del.
Does the word joven change if we are talking about a mother instead of a father?
Why do we use es instead of está to say 'is young'? Isn't youth temporary?
Even though people age and youth doesn't last forever, Spanish treats age and physical descriptions as core characteristics of a person. For physical traits and descriptions, you will always use ser (here, es) rather than estar.