Welcome to the word building section of the site which has worksheets meant to help your students learn more vocabulary words. There are several subsections which allow you narrow down your search; they will make the search for the perfect worksheet even easier. This is an amazing word building worksheet with over eighty words that have a similar meaning to the word say. There are a number of activities explained on the website that you can use with learners of any age. If your students are at a lower level, consider removing some of the words so that they do not become overwhelmed with new vocabulary. Perhaps you think the focus of this activity is a little limited but it is just one example of the 231 wordbuilding worksheets available on this topic so you are free to use another one.
After students have a good vocabulary base, you can help them expand it by introducing synonyms, antonyms, prefixes and suffixes. These are simple ways that students can rapidly increase their vocabulary. Most beginners will not have enough vocabulary to draw on for these types of exercises but intermediate and advanced learners can certainly benefit from them. Generally this sort of activity should not be the primary focus of your lesson but rather used as a short warm up or review exercise.