what function has "there" in the following sentence:
There has been an accident
There is ( are/was/were) by itself doesn't really mean much. It's a common expletive (not to be confused with the four letter word )
It's not very necessary but it has a rhythmic, stylistic or syntatical function. There in your sentence does not really refer to a place. The real subject in your sentence is the accident. Expletives are a big part of the English language, even though some poeple argue that they are weak and clumsy and should be avoided.