Flying into multipurpose rooms throughout the nation, Jeff Rubin — also known as "Punctuation Man" — conquers bad grammar of all kinds by introducing grade schoolers to the nuances of punctuation.

On Thursday and Friday, he landed at Santa Susana School in Simi Valley to spread his message of periods, commas and exclamation points.

"Without punctuation, when you write, people can't tell what you feel," said Rubin, a professional speaker and journalist who created National Punctuation Day. "They can't tell what's on your mind. Punctuation is really instructions for readers."

Speaking to the 59 students in Ronda Oster's combined fourth- and fifth-grade class and Jennifer Wu's fourth-graders, Rubin carefully reviewed the role of each of the 13 most commonly used forms of punctuation.

The featured stars were periods, exclamation points, question marks, commas, quotation marks, brackets, parentheses, apostrophes, ellipses, colons, semicolons, dashes and hyphens.

Altogether, he said, there are 32 punctuation marks used in the English language. But most are never used.

Starting with the mother of all punctuation marks, the period, Rubin also led the children through the tasks of the question mark, exclamation point and comma. At the quotation marks, one student offered her sound wisdom.

"My teacher said the words are the chocolate bar and the quotation marks are the wrapper," said Laura Urias, one of Wu's fourth-graders.

Rubin countered with the placement of other punctuation marks when used in quotes. Unlike the United States, "in England, periods are placed outside of quote marks. It's the same thing with the comma," he said.

Rubin and his wife, Norma Martinez-Rubin, also played games with the students to reinforce the information. "Pin the Punctuation Mark on the Sentence" had the kids calling out the appropriate symbols for a sentence.

Rubin, who also speaks on marketing, integrity and customer service for small-business owners, said he founded National Punctuation Day (Sept. 24) in 2004 after years of frustration with how badly edited some publications were. Two years later, he and Norma decided to develop an elementary school program to teach kids about punctuation.

Armed with a grant from an education foundation, Rubin began working with low-income schools in the San Francisco Bay Area, where he and Norma live.

"The one constant, no matter what kind of school I visit, is that the kids want to learn," Rubin said.

Oster, a former principal who returned to teaching because she missed the children, said the program was very helpful to her students.

"Especially for the high incidence of English-language learners, this is difficult stuff," she said.