Word formation creates new words from existing ones using prefixes (mis-, over-, under-, re-, out-, il-, ir-), suffixes (-tion, -ity, -ness, -ous, -ify, -ise), and conversion (using a word in a different class without changing its form). Mastering word families is essential for C1 vocabulary range and accuracy.
Prefixes change meaning without changing the word class. Common C1 prefixes: mis- (wrongly), over- (too much), under- (too little), re- (again), dis- (not/reverse), out- (surpass). Choose the correct prefixed form.