carefully
Comparative: more faithfully Superlative: most faithfully
Yours Faithfully
Faithfully is an adverb and does not have a plural form. There cannot be more than one faithfully.
The servant stayed faithfully by his master, no matter the problem. The novel was translated as faithfully as possible.
I am faithfully yours.
faithfully
Comparative - more reliable Superlative - most reliable.
Dependably and reliably are synonyms for faithfully.
My sister Faithfully prayed to god
I have faithfully served the Lord with all my heart.
It can be... as in the sentence "She followed him faithfully."; in which case she is the subject, followed is an action verb, him is the direct object, and faithfully is an abverb modifying the verb followed.
The correct spelling is "faithfully" (in a loyal manner).