Limitations and common misconceptions about sentence case
The capitalization rule is exact, but people often expect more from an automated converter than plain text-pattern matching can deliver. These are the assumptions built into the tool and the mistakes worth avoiding.
What the tool assumes
It assumes standard Latin letters and the three common sentence-ending marks: period, question mark, and exclamation point. It has no dictionary and no grammar model, so it cannot recognize proper nouns, brand names, acronyms, or abbreviations — it only knows uppercase, lowercase, whitespace, and punctuation.
Misconceptions to avoid
"Sentence case will keep my proper nouns and acronyms capitalized."
It will not. The conversion lowercases the entire text first, so "NASA" becomes "nasa" and "London" becomes "london" unless the word happens to open a sentence. Recapitalizing names is a manual step after conversion.
"Sentence case and title case are the same thing."
They are not. Title Case capitalizes most or all words in a heading ("This Is Title Case"); Sentence case capitalizes only the first word of each sentence ("This is sentence case"). Style guides typically require sentence case for headings in body text and title case for standalone titles.
"Every period ends a sentence."
Abbreviations like "Dr.", "e.g.", or "U.S." also end in a period without ending a sentence. The tool cannot tell the difference, so it will capitalize the word right after those abbreviations as if a new sentence started there.
Where this differs from smart editing tools
Grammar-aware writing assistants use language models to guess at proper nouns and sentence boundaries with much higher accuracy than pattern matching. This tool trades that intelligence for speed, transparency, and predictability: the same input always produces the same, easy-to-explain output.
Text encoding and special characters
Only the standard A-Z / a-z Latin alphabet is recased. Accented letters, emoji, and non-Latin scripts are passed through unchanged, since the tool has no defined uppercase/lowercase mapping for characters outside that range.
Understanding these limits keeps the tool honest: it performs a correct, predictable sentence-case pass, and nothing smarter than that.