It would help to know what grade level lesson plans you are looking for. I'm not sure that I would teach an entire lesson based solely on singular and plural unless we are talking about elementary students. With middle school and high school students, this is really something to slip in with review or as a part of vocabulary practice. I do usually review singular to plural with my 9th graders each year, but it is something we cover briefly. A worksheet might be a helpful lesson tool for this type of lesson. Unfortunately, this is one of those things which just has to be memorized. A brief overview followed by a matching game and a practice worksheet for homework might make a nice lesson on singular and plural.
a lesson plan for grade two class im lookin for