Synonyms and Antonyms Level 4 Vol. 1 – The fun factor of this free vocab lesson will have your kids asking for more practice with synonyms and antonyms. Children help a frog cross a river by hopping on synonym or antonym logs. Synonyms and antonyms of words like secluded, aid and serene are practiced. Fun music, funny character animations, and engaging interaction make this lesson a splash for fourth-graders!