Practice using commas in lists or series with this helpful grammar worksheet! Commas are used to separate three or more items in a list. The serial comma, or Oxford comma, is the last comma right before the coordinating conjunction. Designed for fifth-grade learners, this punctuation worksheet features 10 sentences containing lists. Students will need to add commas—including the serial comma!—to make the sentences correct. Knowing how to correctly use commas is an essential skill for students to master as they work to improve their writing, editing, and communication!