Root of the Week: LOG

The Greek root log, meaning “word,” “discourse,” or “reason.” appears in many English words having to do with language, science, religion, and a wide variety of fields of study.  Log appears in a large number of nouns after the linking letter “o” and followed by the suffix “y,” giving us “-ology,” which denotes a specialized branch of knowledge (as in biology, geology, and mythology). 

We can pronounce the suffix -log two different ways: /lɑg/ (pronounced as "log"), and /lɑdʒ/ (pronounced ad "lodge"). We would use /lɑg/ (pronounced as "log") when the suffix -log occurs at the end of a word (e.g. epilogue). We would use /lɑdʒ/ (pronounced as "lodge") when the suffix -log occurs before a vowel sound (e.g. logic, biology). 

As for the spelling of log and logue, there is a less clear answer. All of these words seem to have roughly the same path, in which they were borrowed from Greek into Latin, then to Early or Middle French, and finally borrowed into English. -logue is a French suffix, so the question here is whether words retained the French suffix -logue, or received the English suffix -log. There isn't a clear answer as to why some words retained -logue and some changed to -log. There are some regional spelling differences, and British English is more likely to keep the -logue suffix, while American English is more likely to spell words with the -log suffix. The two spellings mean the same thing, and interestingly there seems to be acceptance that some words can be spelled with either (e.g. dialogue vs. dialog).