Spelling of some verb-building suffixes
When the verb-building suffix -a is added to two-syllable words like o‘yin and qiyin, the vowel i of the second syllable drops and this is written: o‘yin+a = o‘yna (to play), qiyin+a = qiyna (to torment). When -ay is added to past and sust, the final t drops: past+ay = pasay (to lower), sust+ay = susay (to weaken). When -illa is added to one-syllable words containing the vowel u or the consonant v, it is pronounced and written -ulla: uv — uvulla (to howl), shov — shovulla (to rustle). These changes are shown in spelling too.
“Which sound dropped?”: the teacher names a stem and suffix (qiyin+a); children write the resulting word and point out the dropped sound.