You are not a 'mr' You are a 'Mister# , which is shortened to 'Mr.'. Note the capital letter and the full stop/period after the letter 'r'.
Yes
do you use a capital letter for the word knighted
Yes, it is correct to use a capital letter after the comma in "Dear Sir" as it is used as a salutation at the beginning of a letter or email.
no
A capital letter.
Most people Understand
A capital letter is to start a sentence or when you use a name or place. Lowercase is the smaller of the two types.
You can use "sauter" in a sentence when referring to jumping or leaping. For example: "Le chat a sauté sur le canapé" which translates to "The cat jumped on the couch."
no
Capital is letter in uppercase and everybody use it. In e-mail or chat however... only shouting people use it... *smile*
She always knew how to command attention with her strong presence and elegant style.