There are a variety of facial expressions, like smile, cry, head-nodding。 Let’s take smile as an example, as we all know, smile is the symbol of happiness, so when the teacher comes into the classroom, he or she should wear a smile 。Because in this way students may feel at ease and it is good for teachers to create a harmonious atmosphere for teaching。 For example, when the student gives a wrong answer during the class, if the teacher gives him or her an encouraging smile, the student may feel warm 。on the contrast, if the teacher criticizes him or her with a strict face, the student may feel embarrassed and lose confidence in learning English。 Compared with Chinese and Math, English is comparatively hard to learn, because most primary school students in China have no basis on English。 So our English teacher should keep students’ interest and confidence in learning English。 Coincidentally, smile as a branch of facial expressions has this magic function。 A warm smile can give students a comfortable studying surrounding。 What’s more, different facial expressions have different functions。 So the teacher should choose the right facial expressions during the class。 In all, if the teacher can use the facial expression correctly, he or she may receive an excellent teaching result and the students will have a better understanding。