Question

determine the meanings of related words in a word family: define and purpose — quiz — level c
make a word that describes someone who does something for a very clear reason.
purpose
ful
est
less

Explanation:

To form a word describing someone who acts with a clear reason, we analyze word parts. "Purpose" means intention, and adding the suffix "ful" (meaning full of) creates "purposeful", which fits the description (full of purpose/reason). "Est" is for superlatives (e.g., "best") and "less" means without (e.g., "purposeless" is without purpose), so they don't fit.

Answer:

purposeful (formed by combining "purpose" and "ful")