Learn French: C'est un professeur sévère, mais les enfants sont contents. - He is a strict teacher, but the children are happy.

In French, when a word ending in an "s" (like les) comes right before a word starting with a vowel (like enfants), that "s" wakes up and is pronounced like a "z" to connect the two words. This is called a liaison, and it makes les enfants sound like one flowing word.

Why use les here instead of des?

les is the plural word for "the", so les enfants means "the children" (referring to a specific group of kids). If we used des enfants, it would mean "some children" or just children in general.

Why does the sentence use C'est for "He is" instead of Il est?

When you describe someone's profession and include "un" or "une" along with an extra descriptive word (like un professeur sévère), French uses C'est. You only use Il est if you state the job all by itself, like Il est professeur.

Why is there an "s" on the end of contents?

In French, adjectives have to match the noun they are describing. Since les enfants (the children) is plural, we have to add an "s" to the adjective content (happy) to make it plural as well.

Why is the word order professeur sévère instead of sévère professeur?