How to identify Stop Words?

Stop words are common words that appear often throughout a set of documents but add little information in terms of being able to conduct text analysis. In the English language, examples of stop words are articles such as “the”, “a”, “an”, which are not useful features for performing text-based analysis. Thus, it is best to remove these kinds of words from the corpus before performing Natural Language Processing to reduce the size of the vocabulary and avoid including unnecessary information.