To the core
All the way through, basically.The local government is corrupt to the core and everybody wants the mayor to leave office.
To the contrary
Contrary to what has been stated or thought.Everybody thought that the boy was bored at the dinner but to the contrary he was quite interested.
To the bone
Thoroughly, entirely.I became wet to the bone during the heavy rain.
To the bitter end
To the very end.We stayed to the bitter end and watched our team lose very badly to the other team.
To the best of one’s knowledge
As far as one knows, from one's knowledge.To the best of my knowledge there have been no telephone calls for me today.
To the best of one’s ability
As well as one is able.I always play sports to the best of my ability.
To speak of
Important, worth talking about.We did not do anything to speak of during our summer vacation.
To (someone’s) way of thinking
In someone's opinion.To my way of thinking we should not spend any more money on the new project.
To (someone’s) liking
In a way that pleases someone.The cook in my favorite restaurant always cooks the food exactly to my liking.
To some extent
To some degree, partly.My answer to the professor's question was correct to some extent but it was not what the professor wanted.