4. Every time I take part in a group discussion of try to speak English to someone, I find it difficult to express myself.
(1) every time意为“每次”，相当于each time，引导时间状语从句，意为“每当……的时候”。
Every time he came to Shanghai, he would pay a visit to her.
每次他来上海，总要去拜访她。
相关归纳：
与every time用法类似的词语还有：each time，next minute，the instant，the moment，the last time，the first time，instantly，directly，immediately等也可以引导时间状语从句，表示“一……就”，从句用一般时代替将来时。
The moment I see him, I’ll tell him.
我一见到他就告诉他。
