keep
(verb)
keep + noun
I keep my wallet in my back pocket.
keep + adjective
I asked him to keep quiet.
keep + noun/pronoun + adjective
I like to keep myself busy.
keep + -ing form
I keep thinking about her.
keep + on + -ing form
I keep on thinking about her.
keep + noun/pronoun + -ing form
I’m sorry to keep you waiting.