تفاوت معنایی این دو جمله‌ی She sings as well as playing the piano...

.She sing as well as playing the piano

نه تنها آواز می خواند بلکه پیانو هم می زند..

 She sings as well as she plays the piano

آواز خواندنش به خوبی نواختنش است.