This research aimed at investigating code switching and code mixing of
teacher talk in English classes at SMA N Patikraja. This research was conducted
by using the descriptive method. The participants of the research were 2 English
teachers of SMA N Patikraja. In this research, the data source was from
observation and interview. Observation result was collected when the teacher was
teaching in her classroom by recording the teaching process. Then, interview
results collected after the teacher finished her class. The researcher used
observation to get the answers of in what situation did the teacher used code
switching and code mixing. The researcher used interview to get the answer of
what is the reason of the teacher using code switching and code mixing. The
researcher used video recording to know how many utterances contained code
switching and code mixing. The researcher found that the use of code switching
and code mixing cannot be avoided by the teachers in teaching learning process. It
was beneficial for the students as it can clarify the student‟s comprehension so it
makes them easy to understand the material.