Although many studies have focused on teacher/student linguistic interaction in TWI classroom settings, research studies focusing on student/student linguistic and social interaction in TWI classrooms are still rare. To fill this gap in the research literature, my study explored interactions through observing students and teachers in their classrooms and listening to their voices in the TWI program. My participants were 10 students, three teachers, and the principal of a Spanish/English TWI school in San Francisco. I used a qualitative approach to engage my participants in a dialogue regarding their experiences and opinions in the TWI program. The data collection process consisted of four steps: (a) observing a class for 105 hours, which was six and half hours a day twice a week for three months, and taking field notes; (b) conducting an audio-taped 30-minute face-to-face interview with each student and the teacher using open-ended questions based on the class observations; (c) transcribing the dialogues and having participants review the transcripts for validity and accuracy during a group meeting; and (d) revising the transcriptions based on their feedback. This study revealed that: (a) language mixing positively impacted the learning experience of bilingual children in the Spanish/English TWI program, (b) TWI teachers may benefit from taking a different approach to language mixing in classrooms, and (c) standardized testing is counteracting the TWI school's effort for language equality and is a detriment to fulfilling the philosophy of TWI. My study narrowed the gap in the research literature by showing that the language mixing can positively impact the learning experience of bilingual children in a Spanish/English TWI program. For this reason, my research is significant and adds to the scholarly research in the field of Two-Way Immersion.