You add the two parts together and nothing changes, so it is: Worrying.
Just and the "ing" to the word "worry" the end result is "worrying"
The -ing form is waving.
You would spell value with -ing on the end as valuing.When you add -ing to a verb, and that verb has a silent E on the end, you get rid of the E.
Typing
riding
Tiering
eye ehn gee
Practicing
end ear ing
planning
centering
Picning