When do we use "should" and "could"? At the end of the video, you'll also find a preview of the next 2 videos where modals are used in everyday speech for discussing probability.

The imposing rock faces of Yosemite are very popular with sport climbers, and the rocky heights are also home to the endearing American pika. Mule deer, many with fawns, inhabit the lower valley, which is awash with spring color.

Kate lives in Grand Lake, Colorado, a small town that is considered the gateway to Rocky Mountain National Park. Kate’s friend Tom is inspired by the cold and recent snow to go out and take a plunge in the icy lake!

Every modal verb is a bit different and not all of them can be used in all tenses. We use "may" for permission, but we can use "can" and its conditional form "could" as well.

A relaxing bobcat family is surprised by the appearance of a young black bear. Elsewhere, a raven family is threatened by the presence of a bald eagle circling above their nesting site.

In the wooded valley, a pine squirrel falls prey to the voracious bobcat. Here we find some of the oldest and tallest trees on earth: The giant sequoias, which are now a major attraction for visitors to the park.

Modal verbs are special verbs that go together with action verbs to indicate ability, permission, obligation and more. Let's see how they work.

As spring arrives, the remarkable and deadly poisonous Sierra newt moves to its traditional aquatic breeding grounds. Meanwhile, kingfishers fish the crystal clear Yosemite streams and squirrels play a dangerous game of chase with the hunting bobcats.

Molten granite was cooled and scoured by glaciers, forming Yosemite’s almost surreal landscape with its many remarkable rock formations. Black bears inhabit the park and emerge each spring from their hibernation, ready to begin a new cycle of life.

Audio and video sources can be factual, and can be used as evidence, but they can both be doctored, too. When we don't have the facts, we might have hearsay, but can we trust it?

What's the difference between disinformation and misinformation? And what about misleading information? Find out in this video.

Protected by presidential decree, the breathtaking mountainous terrain of the Yosemite Valley is now a national park, enjoyed by many human visitors, while still home to the wild creatures and stunning vegetation that has inhabited it for millennia / centuries.

Isaac and his dog, Bucket, are our guides for a road trip across the great open landscape that forms the United States of America. From vast swathes of Kansas farmland and Colorado’s Rocky Mountain ranges to the expansive salt flats at Bonneville, we’re certainly getting a taste for the open road!

Sigrid talks about the reality of conversing with someone who has Alzheimer's. They often have trouble finding the word for the thing they are thinking of.

Nigella finishes her recipe for poached peaches full of pink syrup and fabulous summer flavor!