An elderly sometimes need special care.
an (the)
No candidate fulfils all the criterions for this position.
criterions (criteria)
The master bedroom is filled with several antique furniture.
several
Knowledge was passed from one generation to another generations over the centuries.
generations
The doctor refrained from giving him an advice.
an
A island in the Pacific Ocean was used for the experiment.
a (an)
The import of children´s play is reflected in their behavior
import (importance)
The police officer gave some advices on crime prevention at the community meeting.
advices (pieces of advice)
Wolfs hunt in groups known as packs.
wolfs (wolves)
The exploration was a big, well-built man
exploration (explorer)