In "The Mother Tongue," Bill Bryson discusses the debate over splitting infinitives in English grammar, highlighting the reasons some people oppose this practice. He presents two key arguments against splitting infinitives: first, that it aligns with outdated grammatical rules from a long-gone language, and second, that it reflects an unnecessary adherence to outdated customs that lack support from modern authorities.

Bryson emphasizes that following these old rules can often lead to awkward, unclear, and convoluted sentences. He suggests that such rigid adherence to traditional grammar can undermine effective communication, ultimately proposing a more flexible approach to language that accommodates clarity and elegance over strict conformity.