Both are proper ("correct" ) sentences, the first means that the existance is continuing to be diminished, the second means that it happened in the past but the process is not continuing now.
It depends how you use it. If you use it after something it can be correct. But being in a sentence by itself isn't correct.
Being able is the correct version of the sentence. You can use it as a fragment of any sentence.
a correct sentence
No, the sentence should be: "She dislikes being lied to." This is the correct way to express that someone doesn't like being lied to.
The eight "verbs of being" are: am, is, are, was, were, be, being, been. These are used to depict existence or identity in a sentence.
"Thank you for being so patient." That is correct.
No, the correct way to say it is "be a human being."
Technically neither one is incorrect. It is more grammatically correct to use this sentence; He felt he was being mistreated.
The use of the word in the sentence you quote is in the sense of having been perceived as being rude to an elder. So yes, the sentence is correct.
Yes, that is correct!
The correct phrase is "On the same plane". A plane in this case being a level of development, existence, or achievement.
The past tense of the verb to exist is existed(was real, was in place).