In this video, the teacher explains how to read words with the R controlled syllable "er." They emphasize the importance of not separating the syllable into two separate sounds, but rather creating a whole new sound. The teacher provides examples and guides students through the process of decoding words with "er" by breaking them down and blending the sounds together. By the end of the lesson, students will have a better understanding of how to read words with the "er" syllable.