The spelling of the word "wooler" can often be confusing for English language learners. In fact, the correct spelling of this word is "woolier." The IPA phonetic transcription of this word is /ˈwʊl.i.ər/. The "o" and "e" make the "u" sound, while the "i" indicates the long vowel sound in the middle syllable. The "er" at the end of the word indicates a comparative form of something that is made of or covered in wool, like a sweater that is woolier than another.