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 the harvest ends and the Christmas season approaches, families across the United States come together to share a lavish meal in the annual celebration known as Thanksgiving. In this video, we learn some of the crucial vocabulary used at this special time of year.

Let's look at how Long Island was formed around 20,000 years ago. It has to do with a glacier that brought plenty of material along with it and left some behind when it receded.

Try to figure out what Sigrid is thinking of as she describes something. Understanding the description is just as important as guessing the answer.

Both the Mississippi River and the Colorado River have a huge impact on the lives of millions of Americans. While there have been severe droughts leading to a lack of drinking water, there have also been floods because of quickly melting snow.

Annette explains what colloquial contractions are, and shows us three popular ones: "kinda," "wanna," and "gonna." She tells us where these words come from and how they're used in context.

Yabla wishes everyone the happiest of holidays! Here is some Christmas vocabulary to learn at this special time of year.

Get ready for another round of "Think Fast!" Sigrid will describe some objects and you have to figure out what each object is. Even if you don't know the word for it in English, you are still doing great if you can visualize the object being described.

This episode of "Think Fast" is dedicated to the summer and the heat. Try to guess what Sigrid is describing!

What is the passive voice all about? Sigrid takes us through the basics, step by step. In the active voice, we focus on "who" does something and in the passive voice we focus on "what" someone does.