There's one more important question word to learn: "how." Sigrid provides plenty of examples of questions with "how," both by itself and together with an adjective or adverb.

Sigrid, here as Rita and Kathy, has fun practicing the 5 question words ("who," "what," "where," "when," and "why") on a train. She makes quite a nuisance of herself, too. More about the 5 W's in: Parts of Speech: Question Words - Part 1 of 3.

We often use question words to ask questions. The five main ones start with "wh." Sigrid explains how they work.

The narrator explains how the breathtaking rock formations of Antelope Canyon came to be, and why mountains around the world can provide a metaphor for human existence.

We visit Bryce Canyon, where valuable fossils have helped understand the geological history of the planet. The sandstone spires of the canyon are breathtaking.

In this segment, we learn about the role weather plays in the creation of rock formations in the national parks of the United States.

Geysers represent a very popular tourist attraction in Yellowstone Park. How do they work and where do they come from? And what is sandstone? The video answers these questions.

Why are some rock formations and animals found on more than one continent? The explanation dates back to the Ice Age.

Why do some of the national parks in the United States resemble the European Alps? Geologist Dr. Robert Darga answers this question.

Maggie decides to intervene, and finally the girls are encouraged to stop sulking and talk about their issues.

It turns out that Rachael is also unhappy, and Maggie is feeling more and more uncomfortable about being in the middle of things.

Living together can be challenging, even for good friends. Maggie, as a guest and friend, can't help but notice that Julia is feeling frustrated about something.

The three friends have breakfast together, do some catching up, and muse about the future. Who knows, will they all end up living together in Berlin one day?

The three girls are happy to be reunited, and Maggie gets settled into the apartment. She feels lucky to have such good friends.

Julia and Rachael are young American women living in Berlin. Maggie, a friend of theirs from the United States, is coming for a visit. They are pretty excited about Maggie's arrival.