How to use an adverb correctly

Correct Usage of Adverbs
Incorrect :
Everybody feels contentedly. Correct : Everybody feels contented.'; return false;">Correct :
He seems happily.
Correct : He seems happy.'; return false;">Correct :
She looks sadly.
Correct : She looks sad.'; return false;">Correct :
This food tastes sweetly.
Correct : This food tastes sweet.'; return false;">Correct :
That milk smells sourly.