In the word 'careful', which is the base word or root that combines with the suffix '-ful'?

• A. full
• B. careful
• C. careless
• D. care

Answer: (C)

Think about what a suffix does: it attaches to a base word to create a new word. The suffix -ful means “full of.” When you form the word careful, you start with the idea of care and add -ful to it. So the base that combines with the suffix to make careful is care. That’s why care leads to careful, meaning “full of care.” The other options aren’t the starting base for this suffix: full is a separate word and doesn’t serve as the base here; careless uses a different suffix (-less) to mean “without care”; care by itself is the base concept but doesn’t include the -ful ending.