三明治教学技巧是指在外语教学中，为了将所学内容更快更准确全面地传达给学生，老师在介绍某个新的外语语言点的时候，在将此语言点用外语口述两遍的中间加入一遍用学生母语给出的翻译。插入母语翻译的时候，老师可以有意地通过声调的调节或者停顿等方式来区分外语教学的部分。

三明治教学法的基本操作步骤如下：比如说老师在领读一段对话的时候，老师先用外语 (L2) 领读一遍，然后插入一遍母语 (L1) 翻译，然后再用外语 (L2) 领读一遍，即：L2 => L1 => L2 ，最后让学生用外语跟读一遍此内容。下面以一个简单的短语为例：

In foreign language teaching, the sandwich technique is the oral insertion of an idiomatic translation in the mother tongue between an unknown phrase in the learned language and its repetition, in order to convey meaning as rapidly and completely as possible. The mother tongue equivalent can be given almost as an aside, with a slight break in the flow of speech to mark it as an intruder.