It can be seen that "bilingual teaching" refers to mastering a second language by learning subject knowledge (for example, chemistry, mathematics, computer, etc.). ) using two languages as teaching media. Therefore, "bilingual teaching" is not a simple mother tongue plus a second language, but to cultivate students' comprehensive second language ability from listening, speaking, reading and writing, and to cultivate students' ability to think and solve problems in a second language. Its essence is to use teaching language to promote the development of students' language ability.
In China, "bilingual teaching" refers to the teaching of subjects in which foreign languages are the main language except Chinese. Most of them are in English at present. It requires teachers to explain knowledge in correct and fluent English, but it does not absolutely exclude Chinese, so as to avoid students' thinking obstacles caused by language lag. Teachers should also use nonverbal behavior to prompt and help students understand the teaching content intuitively and vividly, thus reducing the difficulty of students' English understanding. Unlike Singaporean, Canadian, Indian and other bilingual countries, China pays equal attention to both Chinese and foreign languages, so the bilingual teaching environment in China determines its purpose and belongs to the category of "foreign language" teaching rather than "second language" teaching. "Bilingual teaching" in China should belong to "maintenance bilingual teaching".