运用语言学知识分析下面的英语句子,

题目

运用语言学知识分析下面的英语句子,
A:Can you open the door?B:Yes.但B没这么做.这里讲到了什么语言学知识,你对B的言论有什么反映,为什么?

答案

讲的是 speech act theory (语言行为理论）,I would be angry with B,can you open the door is a request of the hearer to do it rather than a question about his ability.The fact he answers yes but doesn't do ot shows he declines my request.