* No single definitive dictionary: There are many dictionaries, each with varying word lists and criteria for inclusion.
* Changing language: The English language is constantly evolving, with new words being added and old ones changing in usage.
* Definition of "word": What constitutes a "word" can be debated. Do we include proper nouns, abbreviations, technical terms, slang?
However, you can get an idea of the scale:
* Estimates: Various sources suggest there are thousands of three-letter words in English. Some estimate around 4,000.
* Examples: You can see the abundance of three-letter words by considering common ones like "the," "and," "but," "for," "her," "him," etc.
Finding a list: There are online resources like word lists and dictionaries that might allow you to explore the possibilities and generate a more specific number.