She looks as if she is sick??? conditional or factual?

[keannu]

Thank you so much for your help.But still I don't understand the below.

He acts as if he were the boss.

I understand "is" can be used for both unreal and real situations, but I still don't understand if "were" is for presuming the opposite of the fact like in the if clause "If he hadn't come=actually he came".

[5jj]

But still I don't understand the below.

He acts as if he were the boss.

I understand "is" can be used for both unreal and real situations, but I still don't understand if "were" is for presuming the opposite of the fact like in the if clause "If he hadn't come=actually he came".

All I can say is than in my opinion, the use of neither 'is' nor 'were' explicitly tells us whether he actually is the boss.

As I said in a previous post, "The reality of the main clause does not depend on that of an as-if-clause". The use of 'as if' in itself casts doubts on the (f)actuality of what follows. This is perhaps why usage here is less fixed than with conditional sentences. It is not possible to be 100% clear abot a situation that is presented as unclear.

He is acting as the boss. - He is not the boss, but he has taken on the boss's role.
He is acting like the boss. -His behaviour is similar to that of the boss.
If he is the boss, then he will know the answer. - There is a possibility that he is the boss.
If he were the boss, he would know the answer. - It is unlikely, or not true, (depending on the context) that he is the boss.

He acts as if he is/was/were the boss. - We do not know for certain whether he is the boss.

I think that, for some people, 'is' in that last sentence' conveys more of an idea that he is the boss, and that 'was/were' convey more of an idea that he is not the boss. However, I also feel that these ideas would not be conveyed to some people.

I suspect that the writer of the grammar book you are using is trying to make a 'rule' based on logic rather than observation.

I must stress that I have used 'I feel', 'I think', 'I suspect' and 'in my opinion'. Neither my grammar books nor the corpora have given a clear answer. And, I have to say, the more I think about it, the less certain I become of even what I say myself.