Two Greek roots fill the pages of every school. log (also logy) means “word,” “reason” or “study”: biology is the study of life, logic is reasoning and a dialogue is words between people. graph (also gram) means “write” or “draw”: an autograph is written by yourself, a biography is a written life and a telegram is writing sent from far away.
Key idea
log, -logy = word, speech, reason, study. graph, gram = write, draw.
At the end of a word, -logy usually means “the study of”: biology (life), geology (the earth), anthropology (human beings). Elsewhere, log usually means word or speech: a eulogy is good words, a monologue is one person’s speech, and an analogy compares one thing to another by reasoning.
The parts and their words
Words taken apart
| Word and meaning | Parts, and what they say |
|---|---|
| eulogy a speech of praise, especially for someone who has died | eu- good + log word + -y → “good words” |
| analogy a comparison that explains one thing by its likeness to another | ana- according to + log reason + -y → “according to reason (a matching proportion)” |
| anthropology the study of human beings and their cultures | anthrop human being + -logy study of → “the study of human beings” |
| chronological arranged in order of time | chron time + log reason, order + -ical → “in time order” |
| biology the science of living things | bio life + -logy study of → “the study of life” |
| dialogue a conversation between people | dia- between + log speech → “speech between” |
| autograph a person’s own signature | auto- self + graph write → “self-written” |
| biography the story of a person’s life written by someone else | bio life + graph write + -y → “life writing” |
| telegram a message sent by wire and printed | tele far + gram written → “written from far away” |
Worked example: Build a word
A biography is a life story written by someone else. What do you call a life story a person writes about himself or herself?
- Start with bio (life) + graph (write) + -y.
- Add auto- (self) in front.
- auto- + bio + graph + -y: a self-written life.
Answer: An autobiography.
Meet the words
Common mistake
Reading every log as “study of.” -logy at the end of a word usually means the study of (biology), but log elsewhere often means word or speech: a eulogy is not “the study of good”; it is a speech of praise.