The British spell it "skilful".
The British spelling of skillful is skillful in a British accent
That is the correct spelling of the adjective "skillful" (talented or competent).
The British speak and use the English language so it would be spelled as skillful.
The adverb form is spelled skillfully, from the adjective skillful.
Skilful (UK spelling) / skillful (US spelling) is not an adverb, no.Skilful/skillful is actually an adjective.The adverb form is Skilfully (UK) / skillfully(US).
The British spellings for theater, honor, pajamas, and skillful are: Theatre Honour Pyjamas Skilful
That is the correct spelling of "talented."
The word is spelt as you have in the question. As it happens, there is no difference between the American spelling and British spelling of the words.
The British English spelling of marvelous (astonishing; wonderful) is marvellous.
British spelling: meagre
Savior is the American spelling. Saviour is the British spelling.
Apologized is the American spelling, and apologised is the British spelling.