FORMAL register is used in speeches and presentations, as opposed to discussion, that demands precise technical jargon.
CONSULTATIVE register is language more often used in dialogue that includes some off-hand, informal language, impromptu corrections and non-technical explanation.CASUAL register is used in group discussions with friends that can include gaps, interruptions, pauses, errors and personal “inside” words.
INTIMATE register is used in private conversation between close friends and family where tone, volume and unspoken hints or suggestions may be just as important as the denotation of words.
Examples: “Honoured guests, members of the board, Superintendent Johnson, and most importantly, graduates of the class of 2012, it is an honour to speak to you on this occasion.” The predominant register here is the Formal register, since it's a speech and it addresses "Superintendent Johnson"
“While I was pleasantly surprised by the menu selections for dinner service, I was disheartened by the lukewarm eggs at breakfast.” This sentence is based on a Casual register since the speaker is giving us a personal opinion.
“Yeah, right” This affirmation falls into the Casual register since it gives a correction or personal thinking of himself.
“I doubt it” This correction falls into the Consultative register since it gives an announcement against some fact.
“I’m tired of your rubbish” Intimate register since it expresses something from the deep of someone “I’m tired” Intimate register since the narrator is telling his/her mood at the moment.
