Learn Italian: I ragazzi non sanno sciare. - The boys do not know how to ski.

When using sapere to express that you know how to do a skill, you simply place the infinitive verb (like sciare) right after it. You don't need extra words for "how to." The phrase sanno sciare literally translates as "they know to ski."

Is sanno a regular verb?

No, sapere (to know) is an irregular verb. A regular "-ere" verb for "they" (loro) would normally end in "-ono," but sapere completely changes its stem to become sanno. You just have to memorize this special form!

Where exactly does non go when there are two verbs in the sentence?

The negative word non always goes directly in front of the conjugated verb. Even though sciare (to ski) is also in the sentence, non must go right before the main action sanno, making it non sanno sciare.

Can i ragazzi refer to a mixed group of boys and girls?

Yes! While it literally translates to "the boys," Italian uses masculine plural nouns for mixed groups. So i ragazzi is very commonly used to mean "the kids," "the youth," or "the guys" regardless of everyone's gender.