ROOT WORDS CAN HELP YOU UNDERSTAND THE MEANING OF WORDS AND WHERE THEY COME FROM.  A ROOT WORD CAN HAVE AN AFFIX (PREFIX OR SUFFIX) ADDED TO IT TO FORM A NEW WORD.
COMMON LATIN ROOTS COMMON GREEK ROOTS
ROOT WORD MEANING EXAMPLE ROOT WORD MEANING EXAMPLE
CENT 100 PERCENT CHRON TIME CRONIC 
CIRCUM AROUND CIRCUMSTANCE GRAPH WRITING GRAPHIC
DUCT  TO LEAD CONDUCT MORPH FORM; SHAPE MORPHING
FORM SHAPE REFORM NYM NAME SYNONYM
FORT STRENGTH FORTRESS METER MEASURE THERMOMETER
PORT TO CARRY PORTABLE PHOB FEAR PHOBIC
SCRIBE TO WRITE PRESCRIBE PHON SOUND SYMPHONY
SECT TO CUT BISECT SCOPE SEE, WATCH MICROSCOPE
SPECT TO LOOK INSPECTION THEM  HEAT THERMAL
STRUCT TO BUILD RESTRUCTURE HYDR WATER DEHYDRATE