Try focusing on lower case letters when you are teaching a child.  Most of the text that children have seen as you read books to them is lower case.  Normally, only the beginning letter and the beginning letter of proper words are capitalized.  For example, focus on sight words in lower case in familiar books, refer to the video on teaching sight words at http://www.abcsforliteracy.com/ homepage.

Simple tips for children, ages 3-6, to learn to read and write:

Many early learning tools focus on upper case letters, but at abcsforliteracy.com, our educators suggest focusing more on lower case letters.  When you read to children, all the text is lower case letters except for the beginning letter of a sentence and proper names.  Thus, when your child is learning words, most of the time, the text will be in lower case letters.  Refer to the alphabet sounds pictures, on our homepage at http://www.abcsforliteracy.com/, that have lower case letters as a prompt for the child as a good tool to practice the lower case letters with your child.