French language Q&A Forum

I think it's interesting that you never note the divergence of french and english grammar on using bien as an adverb with être.  If one says in english  "it is good", good is an adjective.  If one says the french version of this "C'est bien" one uses the adverb. Elsewhere in french "c'est" is followed by an adjective "c'est beau". Usually, I guess, one uses il/elle "il est difficile".   But it seems unusual to suddenly use an adverb to describe not a verb but the noun of the sentence.  I can see easily Ça va bien, because bien is modifying the verb going. 

Apercevoir/s’apercevoir:  to glimpse, to see, to take note of

All mean more or less the same in English. Are they interchangeable in French or are there subtle differences?