The spelling of the word popul can be a bit tricky. When pronounced, it sounds like pop-yull, with the stress on the first syllable. The IPA phonetic transcription for this word is /ˈpɒpjʊl/. The reason for the spelling confusion is that the Latin root word popul(us) means "people," and the word popularity, derived from populus, is probably more familiar. So, when spelling popul, just remember to drop the -ar ending of popularity and substitute -ul instead.