This is a very brief PowerPoint reviewing when to use "s" with third-person singular pronouns for present tense. I was asked to make this quick review because my high school students forgot about this grammar point from junior high, and were having trouble with it on their tests. I didn't know the rules personally when to use "s", so I hope other ALTs find this helpful.
Note: I know there has been a lot of contention about the use of "they" as third-person singular. I chose not to include a slide on it for this post because my original PowerPoint did, and it was too advanced for my students (they're doing similar coursework as elementary school students).
However, if your students are advanced enough, you may want to include a slide about how "they" can be used as third-person-singular. Especially for those whose students may study abroad for college because "they" as third-person singular is very common in academic writing. It has been approved since 2011 for use in writing style guides used in college-level writing courses such as MLA and APA.