Learn French: Ils sont prêts et contents.

Ils is the masculine plural pronoun, used for a group of males or a mixed group of males and females. Elles is the feminine plural, used only for a group of exclusively females. When the gender of the group is unknown or mixed, French always defaults to ils.

How do I know sont means "are"?

Sont is the plural "they" form of the highly irregular verb être (to be). Just like you previously learned je suis (I am) and il est (he is), you have to memorize that ils sont means "they are".

Why is there an s at the end of prêts and contents?

Adjectives in French must change to match the subject they describe. Because the subject ils is plural (more than one person), you must add an s to the singular adjectives prêt (ready) and content (happy) to make them plural as well.

Are the s endings on ils, prêts, and contents pronounced?