Annette offers an array of ways to greet people, from sunup to bedtime. Ways of greeting people vary from place to place, but Annette provides one general rule — greetings must be cheerful and friendly.

In this video, Sigrid looks at certain kinds of questions in which it is correct to use "some," the dreaded double negative, and negative statements that can be expressed in two different ways.

Some and any both refer to an unspecified quantity, but they are used in different situations. Sigrid explains how they work.

Sigrid explains the meaning of "prop" as both a noun and a verb. Either one can come in handy.

In American schools, it's common for kids to have to learn the Preamble to the United States Constitution by heart. This song, from Schoolhouse Rock, is meant to give these kids a hand, even though it is a slightly abridged version.

Here are some words to help answer the question "Which one?" We distinguish between singular and plural as well as between something close to us and far away.

This song was written and sung by Bob Dorough. It teaches about the multiplication of 5 through a game of hide and seek, in which the seeker counts by fives.

Bob Dorough wrote and sang this song about the number "three," as a fun way for kids to learn their multiplication tables. It became the pilot episode for Multiplication Rock, the first season of the Schoolhouse Rock TV series.

Nouns are usually the first words we learn. The good news is that with nouns, we don't have to worry about gender in English. We do, however, have to be aware of gerunds that act like nouns but look like verbs, and countable or uncountable nouns.

Anna, from Cambridge University Press, explains how and when to use the Present Simple.

Annette explains three more colloquial contractions people use in everyday conversation: gotta [got to], gotcha [got you], and dunno [don't know]. She also gives us examples in context.

This song from Schoolhouse Rock is to help kids understand about bones. Without bones, we're just blobs. It was written by George Newall and sung by Jack Sheldon.

This song teaches about the digit 0, portrayed as a superhero, as well as multiplication by powers of 10. This song was voted the 11th best song on the 30th anniversary edition. Sung and written by Bob Dorough.

Sigrid explains what a limerick is, and how to write one. If you are so inclined, you can submit your limericks in the "comments" section of the video tab.

Career expert Nicole Williams explains the most important question in an interview and the kind of answer the interviewer is looking for.