Interesting fact: English grammar requires verbs to agree with their subjects in number and person. While informal speech often uses contractions like "don't" more broadly, standard written English dictates specific usage based on the subject's form. Mastering these agreement rules, particularly with third-person singular subjects (like 'she', 'he', 'it', and singular nouns) which require "doesn't", is crucial for formal writing and demonstrates a strong command of grammatical conventions.
