M. Swan suggests that it is not required in the given sentences:
1- They lost money, as (it) was expected.
2- The train may be late, as (it) happened yesterday.
3- As (it) is well known…
4- As (it) is in your knowledge that a new campus is…
I would like to know if it is wrong to put it here or there is also a difference of opinion somewhere! Secondly, he does not deal with this topic in detail. Look at the given sentence please.
1- The train may be late, as (it) was yesterday.
What about this one? Even it is wrong here?