2 Syllables: SU
dwelling, Elgin, felling, Helen's, helping, melting, Melvin, pelting, selling, shelling, shelving, smelling, smelting, spelling, swelling, telling, welding, welling, yelling
3 Syllables: USU
compelling, dispelling, excelling, expelling, foretelling, impelling, indwelling, propelling, rebelling, repelling
4 Syllables: UUSU
Found 30 words across 3 groupings. Skipped 2 excess words of a similar stem.