Complex sentence: Wichita, for instance, possesses a vertical vowel system; however, two of the vowels it uses (e and i) are phonetically fronted, and the other (a) is phonetically backed.
Split into simpler sentences: Wichita, for instance, possesses a vertical vowel system. However, two of the vowels it uses (e and i) are phonetically fronted, and the other (a) is phonetically backed.