We have this wonderful language and we don't appreciate it. That's old-fashioned me, but when I went to school, everyone had elocution lessons, not to sound posh but so you could be understood.
Your work isn't just to learn and say the lines. Your work is to figure out what the chatter in your brain is, that's going on under the lines. It doesn't matter whether you're speaking or not speaking because your mind is working the way your character's mind would work.
The amount of detailed information which an individual has at his command and his theoretical elaborations of the same are mutually dependent; they grow in and through each other.