Talk:The New Aliens/@comment-24922135-20170129190008/@comment-24922135-20170129210129

well your example is bad since the sentence could be written as "X is walking and Y is talking."

most of the time ", and" is bad grammar because it isn't needed. The key word is 'most'

Commas can be used to upwards of double the length of a sentence, same with 'and'. So in this scenerio he used two sentence-connecting words, which breaks up the flow of the sentence for the benefit of adding four words onto it.