A good explanation of Plural Forms for the student. Site also offers a quiz at the end. L.11-12.2b Spelling

Possessive plurals have a complicated relationship with apostrophes, but this exercise is here to help you understand it!

In this learning module, students will read how to use the indefinite articles "a" and "an" with singular count nouns. They omit these articles with noncount and plural nouns. The students then practice using "a" and "an" correctly.

Rules and examples for changing nouns from singular to plural.

What is an apostrophe? Where are apostrophes found in writing? Use this website to learn more about these crazy little punctuation marks.

Resource explains the three uses of the apostrophe and provides examples. Requires Adobe Reader. [PDF]