Chris Pratt and Aubrey Plaza talk about their roles from the hit TV series Parks and Recreation. Their characters Andy and April became a couple in the second season of the show, but early on it was unclear if they would have the necessary chemistry.

As the series draws to an end, the young actors reflect on their onscreen relationship, and how their characters have matured. Chris Pratt makes it clear that this time in their lives has been tremendous fun, but also a deeply formative and moving experience.

Here's a quick summary of the different kinds of words we have in the English language and what they are used for.

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.

Sigrid reviews the subject pronouns "I," "you," "he," "she," "it," "we," "you," and "they."

Sigrid reviews the object pronouns: "me," "you," "him," "her," "it," "us," "you," and "them."

Sigrid talks about the difference between possessive nouns and other possessive words such as possessive determiners or articles like "my" and "your."

Sigrid takes us through the different persons using dependent possessive pronouns, also called possessive adjectives or possessive determiners. These little words are important when talking about names, your possessions, family and friends, characteristics, jobs, favorite things and just about everything else.

True possessive pronouns can stand alone. They replace both the noun and its possessive adjective or determiner. These pronouns are very handy in introductions and conversations about favorites.

"One" and "ones" can replace nouns, but are not pronouns. They are prop words. Let's look at how they are used.

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.

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

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

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.

Sigrid goes over examples in which "no" takes the place of "not any." As always, you have to watch out for double negatives.