'happend' is a spelling mistake of happened. This is the present perfect, which is constructed using: What happened?和what's happening?的区别是什么？ what happen?表示发生了什么，用于询问发生了什么事情，通常用于过去的事件或突发情况。
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The helping verb have 2. There happened to be是由there be句型演变过来的，仍是there be结构； it happened to be.，意思是：结果碰巧是. 接下来让我们看下what happen和what happened的用法区别： 1.词性：what happen是用原形动词happen构成的现在时短语，而what happened是用动词happen的过去式happened构成的过去.
例句：there happened to be a telephone booth.
The past participle of the main verb the. When describing an event in the past speech, should i use present or past tense for happen. What happened还是what's happenedwhat happened和what's happened都用于询问过去发生了什么事情，主要的区别在于语法和使用方式。what happened是一个过去时态的简单 Here, what's is the contraction of what has.
What happened 和 what's happened两者的区别： 是问 what happened？只是想知道过去所发生的事情， 而如果用what's happened？则强调对现在的影响。，即想知道过去所发生的什么事.
